Understanding the DRDP access Measurement Model

Developed by the Desired Results access Project – A Special Project of the Napa County Office of Education. Funded by the Special Education Division, California Department of Education. January 2008

The measurement model used to guide the development and validation of the DRDP access differs from many assessment instruments used in early childhood programs. This paper provides an overview of the DRDP access and the measurement model on which it is based. The purpose of this paper is to help assessors understand the benefits of the DRDP data collection and reporting system and the importance of the information it provides.

Table of Contents

• The DRDP Instruments
  • Principles Guiding the Development of the DRDP access
• The Statistical Measurement Model Used with the DRDP access
  • Instrument Construction
  • Interpreting the Results
• Overview of Developmental Status Reports
• Benefits of the DRDP access
• References
• Calculating Ability Scores
• Calculating Scale Scores
• Calculating Logits
• Glossary

 

Top

---

The DRDP Instruments

In 1996, the Superintendent of Public Instruction asked all California Department of Education (CDE) programs to increase program accountability. This included identifying program standards and learning guidelines that would lead to desired child and family outcomes as well as revising the program monitoring system to include assessment of progress toward child outcomes. Following the Superintendent’s request, four Desired Results were identified as conditions of well-being for children enrolled in California’s state-funded infant/toddler, preschool, and after-school programs, including programs for children with disabilities. The CDE Special Education Division (SED) entered into a collaborative effort with the CDE Child Development Division (CDD) to develop assessments for monitoring the progress of children enrolled in state-funded programs toward these Desired Results. The result was the Desired Results Developmental Profile (DRDP) instruments. Currently, three versions of the DRDP-R (Desired Results Developmental Profile – Revised) are used in CDD programs:

• Infant Toddler (I/T) – Birth to 36 months
• Preschool (PS) – 3 years to Kindergarten
• School Age (SA) – Kindergarten through 12 years

A fourth version is the DRDP access, which is for three, four and five-year-old children with IEPs who receive preschool services. Some preschool children with IEPs do not yet demonstrate the skills that make up the Preschool DRDP-R. As a result, it was necessary to develop a DRDP instrument that would cover the developmental range of birth to five years. The DRDP access was developed by combining the Infant Toddler DRDP-R and the Preschool DRDP-R. Because these two instruments differ somewhat in content, the resultant DRDP access might best be thought of as a hybrid of the two. SED is using the Preschool DRDP-R and the DRDP access to meet accountability requirements of the Individuals with Disabilities Education Improvement Act of 2004 (IDEA 2004). Children in SED-funded programs are assessed with the DRDP instruments two times per year.

Principles Guiding the Development of the DRDP access

The DRDP access includes 48 items (referred to as Measures). Each Measure covers a specific developmental construct or aspect of early development (for example, expressive language) and describes a continuum of five to nine distinct levels of development that covers the developmental range of birth to age five. Assessors score each Measure by selecting the level of development that best describes the child’s skills, abilities, or knowledge based on the behaviors they observe, conversations with families, and information collected from other service providers or other assessments.

The following key principles have guided the development of the DRDP access:

• The Desired Results are the same for all children in California
• A basic principle has been that the same Desired Results guide programs for ALL children in California. These Desired Results serve as a framework that guides the development of program and learning standards, curriculum development and implementation, and assessment for the purpose of program improvement. The Desired Results (DR) for children are:
• DR1: Children are personally and socially competent
• DR2: Children are effective learners
• DR3: Children show physical and motor competence
• DR4: Children are safe and healthy

• The content of the DRDP instruments is grounded in the empirical literature related to child growth and development
• On the DRDP instruments, each Desired Result is comprised of Indicators, which are specific, measurable dimensions for each Desired Result. Each Indicator is divided into Measures that represent the developmental sequences of skills along which child behavior is assessed. The continuum of skills associated with each Measure is expressed through levels from earlier development to later development. Figures 1 and 2 below show the relationship between Desired Results, Indicators, Measures, and the continuum of skills for the PS DRDP-R (Figure 1) and for the DRDP access (Figure 2) as represented in the instrument manuals. The PS DRDP-R and the DRDP access (birth through age five) are formatted differently because of differences in the ages covered, yet the developmental constructs assessed are very similar.
• The Indicators for each of the four Desired Results were identified from child development literature. The content of each Measure within an Indicator is based on research related to child growth and development. The skill sequences for each Measure were carefully referenced to the literature and then reviewed by content validation panels made up of child development experts, early intervention/early childhood special education researchers, early childhood and special education practitioners, families, measurement specialists, and program administrators.
• For reporting purposes, data from the DRDP access is reported by Indicator Group. The ten Indicators of the DRDP access are grouped for reporting scores into eight Indicator Groups. The Self-Concept and Social/ Interpersonal Skills Indicators have been combined, and Learning and Cognitive Competence Indicators have been combined, resulting in eight Indicator Groups.

Figure 1: Preschool DRDP-R for Children with IEPs Navigational Map

Figure 2: DRDP access Navigational Map

• Assessment is based on observation of the child’s behavior in typical environments (authentic assessment)
• The DRDP instruments are authentic assessment instruments which means that behavior is observed while children are engaged in real-life tasks in typical environments and with familiar adults (Losardo & Notari-Syverson, 2001; Neisworth & Bagnato, 2005). Observation and documentation of child skills during routines and activities in typical environments is a basic tenet of the DRDP instruments. Setting up artificial and adult-directed tasks for the purpose of eliciting particular skills is not an appropriate strategy for completing the instrument. Instead, the assessor is advised to observe children daily and over time, to observe systematically, and to document observations and sources of evidence that inform ratings. The resulting documentation is the basis for rating the DRDP.

• Multiple sources of evidence are gathered over time
• Rating the DRDP instruments should also be based on multiple sources of evidence. Input from others who have on-going contact with the child and know the child well should be obtained over time and should inform the instrument rating. Obtaining information from multiple sources will result in more complete and accurate information about the child’s skills and progress. The assessor needs to establish a mechanism for on-going collaboration with parents, other care providers, and other service providers so that information from these other sources will be included in each DRDP access assessment.

• Assessments are universally designed
• Universal design is “the design of products and environments to be useable by all people to the greatest extent possible” (Thompson, Johnstone & Thurlow, 2002, p.1). Initially applied to the field of architecture, this concept has been adopted by other fields including educational assessment. The Standards for Educational and Psychological Testing (AERA, APA, NCME, 1999) require that each individual being tested be given a “comparable opportunity to demonstrate their standing on the constructs the test is intended to measure” (p. 74). One way to address this aspect of equity or fairness is through the application of universal design during the content development of assessments so that the results are not affected by race, gender, disability, or English language ability. Adhering to the principles of universal design reduces the need for “retrofitting” assessments with large numbers of adaptations (Thompson et al, 2002).
• As part of the development of the DRDP access instrument, the wording of items associated with each measure was reviewed to ensure that it did not preclude a rating of “mastery” for children with physical, sensory, cognitive, communication or social-emotional disabilities, while still reflecting the intent of the item. After universal design principles were applied by the developers, each item on the DRDP access was reviewed by two experts who made additional suggestions for wording changes that would make the instrument inclusive of children with disabilities and children from culturally or linguistically diverse backgrounds. Measures on the DRDP access have been statistically compared across groups to ensure that they are equitable. This statistical testing is still in process.

• Use of adaptations are permitted to ensure appropriateness for young children with disabilities
• Adaptations include changes made to the environment and the provision of alternate response modes that allow children with disabilities to demonstrate skills that they might otherwise not be able to demonstrate. Adaptations facilitate the measurement of children’s abilities rather than their disabilities. For example, a child with impaired vision who needs additional lighting to see objects or text will benefit from this change to the environment. Similarly, a child who communicates using sign language is responding in an alternate response mode. IDEA 2004 specifies that the Individualized Educational Program (IEP) must include a statement of any adaptations that are necessary to measure the academic and functional performance of children on a statewide assessment.
• A list of seven adaptations has been identified which includes the following: augmentative or alternative communication system, alternate mode for written language, visual support, assistive equipment or devices, functional positioning, sensory support, alternative response mode. These adaptations are permitted for use with children with disabilities when assessing with either the PS DRDP-R or the DRDP access. Refer to the Desired Results access Project website (www.draccess.org) for a description of the adaptations.

Adaptations used with the DRDP instruments
Augmentative or alternative communication system Alternate mode for written language Visual support Assistive equipment or devices Functional positioning Sensory support Alternative response mode

 

Top

---

The Statistical Measurement Model Used with the DRDP access

The measurement model used with the DRDP access is based on the work of George Rasch (1960, 1966) and is typically referred to as Rasch measurement. The potential utility of Rasch measurement models in early childhood assessment has been recognized for many years (Snyder & Sheehan, 1992) and their usefulness in assessment for early childhood accountability systems has recently been highlighted (Meisels, 2006).

Instrument construction

Identifying the levels within measures.  As indicated above, the DRDP access is made up of four Desired Results which each include one or more Indicators. Each Indicator is divided into Measures. Each Measure consists of a developmental continuum from birth to age five related to a particular developmental construct or aspect of behavior. For example, the Motor Skills Indicator is divided into the four developmental constructs (Measures) of Movement, Balance, Grasp/Release and Manipulation, and Eye-Hand Coordination. When the DRDP access is scored, the assessor determines the highest level of the behavior continuum in each Measure where the child demonstrates mastery.

In developing the DRDP access, it was necessary to determine what behavior should be identified for each level from birth to age five for each of the Measures. These behaviors were identified by reviewing child development research and through consultation with child development experts.

Figure 3 represents Measure 40 – Movement, from the Motor Skills Indicator of the DRDP access as it was originally developed. In Figure 3, the arrow on the right represents the continuum from early development at the bottom to later development at the top. As can be seen from this arrow there is a qualitative order to levels on the continuum of the Measure (the levels are represented in the shaded boxes on the left). The levels range from developmentally less advanced (at the bottom of the line) to more advanced (at the top of the line). Each level on the continuum was determined from theoretical and empirical child development literature. The skills at the two extremes on the continuum were specified first, followed by specific skills at levels between the two extremes. In the example in Figure 3, the lower extreme is “reflexes dominate movements.” The upper extreme is “participates in extended or integrated physical activities.” This sequence of levels from the bottom up represents the development of movement skills in children from birth to 5 years. The DRDP access includes 48 Measures, all of which have between five and nine levels that were developed in this manner.

Figure 3: The “Developmental Ruler” Illustrating the Development of the Movement Measure

Calibration.  The sequences of development identified for each Measure, as illustrated in Figure 3, would be helpful for assessing child progress as they are originally formulated. However, the Rasch model requires that the sequences be calibrated. Calibration is the statistical process of marking differences in outcomes along a scale so that numerical scores will be provided. This requires collecting the ratings for each measure from a large group of children (birth through preschool). For the calibration of the DRDP access, 1644 infant, toddler and preschool children from California were assessed. Children with and without disabilities were included in the calibration study.

The statistical process for calibration in the Rasch measurement model is a mathematical procedure based on probability theory. The process asks this question: “What is the probability that a child with a particular level of ability will demonstrate mastery at that same level on each Measure?” An ability score is estimated for each Indicator Group for each child by summing the child’s raw scores for all Measures in the group (an example of calculating ability scores can be found at the end of this paper). Calibration defines the link between the child’s ability level on an Indicator Group and level of mastery for each Measure.

The scores which are derived from calibration are scale scores. Scale scores are raw scores that have been transformed to a new scale so that equal intervals are maintained between each unit on the scale (an example of calculating scale scores can be found at the end of this paper). Figure 4 shows the Movement Measure after calibration. Notice that the scale scores are equally spaced along the Movement Measure. On the left side of the figure are representations of the scores of children from the calibration sample at various levels of ability in relation to the construct. Each X in the figure represents two children from the calibration sample. Child 1, for example, demonstrates advanced ability in relation to the construct being measured, while Child 2 demonstrates less advanced ability. In Figure 4, ability is represented by scores called logits which range from 100 to 300 (an example of calculating logits is can be found at the end of this paper). As indicated above, following the Rasch measurement model, raw scores from the DRDP access Indicator Groups were totaled and transformed to a new scale to provide an equal distance between each point on the scale (equal interval scale). Having an equal distance between each point on the scale is helpful in measuring child progress across time because the amount of progress represented by any two consecutive points is the same. For the DRDP access, the mean scale score for each indictor group is 200 and the range is from 100-300.

Figure 4: The Calibrated “Developmental Ruler” for the Movement Measure

Interpreting the Results

Before calibration (in Figure 3) each of the levels of the Measure is the same size as the others along the “ruler” which represents development from birth through five. However, after calibration (in Figure 4), the levels are different sizes along the ruler. Each level of the measure does not necessarily represent the same developmental distance. This can be seen by looking at the scale scores: level 1 covers 40 units on the scale, while level 2 covers 25, and level 3 covers 5 units. This is important to consider in relation to developmental progress. While the levels on each measure are numbered from 1 to 9 in the instrument manual and on the Rating Record, it would be inaccurate to assume that moving from level 3 to level 4 represents the same growth as moving from level 4 to level 5. However, using the scale scores, increasing from 200 to 220 does represent the same amount of growth as moving from 220 to 240.

Scores on the DRDP access describe a child’s relative position on a developmental path (from earlier developing to later developing). Progress on the DRDP access represents growth or skill development (movement toward higher level skills). This is different than progress as measured by norm-referenced instruments where increased scores represent a change in status relative to “position in a normative group” (Meisels, 2006, p.19), i.e., relative to the scores of children in the standardization population. The DRDP access is administered two times each year. The information provided from this assessment has direct implications for improving instruction because the equal interval scores measure movement toward higher level skills.

The construct map shown in Figure 5 represents all four Measures of the DRDP access Motor Indicator: Movement, Balance, Grasp/Release and Manipulation, and Eye-Hand Coordination. Each of the levels along the progression from earlier developing to later developing for the four Motor Measures is shown on this construct map. The scale scores that pertain to each level of these four Measures are provided on the left. The sequence of the levels was confirmed within each Measure during the calibration study. However, the “distance” between each of the levels is not equal. For the first Measure in the Motor Indicator there is more distance on the construct map for “makes simple movements with parts of body” and less distance for “moves whole body using arms and legs.” When there is more distance on the construct ruler, it means that it takes more development (will generally take longer) to move into the next level.

Because each of the Measures has levels with different distances, a child who demonstrates mastery at level 4 on one of the Measures will not necessarily demonstrate mastery at level 4 on each of the others. We would not expect a child to score at the same level of mastery across all Measures within an Indicator. Although the levels designate increasingly higher levels of achievement within each Measure, they do not necessarily represent a “stage” of development across Measures. The levels also cannot be equated with a particular age in child development. It would not be accurate to try to interpret a child’s growth in terms of age-equivalent scores.

Figure 5: Construct Map of all Measures in the Motor Skills Indicator

Overview of Developmental Status Reports

Data from the DRDP access for each child are entered into a web-based system called the Special Education Desired Results System (SEDRS). A summary report entitled the Developmental Status Report is reported back to programs following each administration. Scores are reported according to each of the eight Indicator Groups: 1) Self Concept and Social Interpersonal Skills, (2) Self Regulation, (3) Language, (4) Learning and Cognitive Competence, (5) Math, (6) Literacy, (7) Motor Skills, and (8) Safety and Health.

Developmental Status Reports have been developed to examine individual child progress and to summarize the data for the service delivery team including family members. Figure 6 provides an example of the Developmental Status Report for a child named Juan Carlos who is introduced here. Information about Juan Carlos is presented to provide the reader with an example of the administration of the DRDP access and the resulting Developmental Status Report.

Figure 6: Developmental Status report for Juan Carlos

The report in Figure 6 includes the scale scores for Juan Carlos for each of the eight Indicator Groups of the DRDP access, the range of scores considered typical for age-matched typically developing children, and a bar representing the total scale for each Indicator Group. The shaded area of the bar represents the zone of typical development and the vertical black line indicates Juan Carlos’ scale score. It should be noted that the zone of typical development is defined as beginning at 1.3 standard deviations below the mean which is consistent with the definition of the functioning of typically developing peers used to report child outcomes data for the U.S. Department of Education Office of Special Education Programs. The zone of typical development, therefore, is inclusive of some children who score below the mean and does not include only those children who score at the mean or above.

From Figure 6, it can be seen that Juan Carlos has areas of relative strength in Self Concept and Social and Interpersonal Skills, Language, and Safety and Health. He has areas of relative need (defined as below the zone of typical development) in Self-Regulation, Learning and Cognitive Competence, Math, Literacy and Motor Skills.

 

Top

---

Benefits of the DRDP access

In summary, a number of characteristics of DRDP access make it a very useful early childhood assessment for families, teachers, and programs.

• The DRDP access measures children’s typical behavior in routine environments.
• The DRDP access is an observational instrument based on the ongoing observation and documentation of child progress by service providers in real life situations rather than in isolated adult-directed testing situations. Information is gathered from multiple sources to inform the rating of the instrument. As a result, the ratings of mastery on the DRDP access are likely to be reflective of the typical behavior of each child across environments.

• The DRDP access measures abilities, not disabilities.
• The DRDP access was developed following the principle of universal design and includes adaptations so that the abilities of children rather than their disabilities are measured.

• The DRDP access helps teachers and parents understand children’s progress.
• The Rasch measurement model has been used in the development of the instrument so that the instrument yields scaled, equal interval scores. Equal interval scores allow comparable estimates of a child’s progress across time. As a result, practitioners and families can determine relative progress in each of eight areas between assessments and can interpret the child’s progress in relation to the development of typical peers.

• The DRDP access informs teaching strategies.
• The DRDP access is made up of items organized logically and sequentially under developmental constructs based on child development research. The instrument is administered twice a year, providing the opportunity to use the results to inform teaching (formative assessment) rather than only as a measure of achievement at the end of a program (summative assessment). The instrument will be linked to the California Learning and Development Foundations so that the assessment will be useful for overall curriculum planning as well as for intervention planning for individual children.

 

Top

---

References

AERA, APA, NCME (American Educational Research Association, American Psychological Association & National Council on Measurement in Education). (1999). Standards for educational and psychological tests. Washington, DC: American Educational Research Association.

Agresti, A. (1996). An Introduction to Categorical Data Analysis. John Wiley & Sons: New York, NY.

Bond, T.G., & Fox, C.M. (2007). Applying the Rasch model: Fundamental measurement in the human sciences (2nd ed.). Mahwah, NJ: Erlbaum.

Bond, T.G. & Fox, C.M. (2001). Applying the Rasch model: Fundamental measurement in the human sciences. Mahwah, NJ: Erlbaum.

Losardo, A., & Notari-Syverson, A. (2001). Alternative approaches to assessing young children. Baltimore: Paul Brookes.

McLean, M., Wolery, M., & Bailey, D. (2004). Assessing infants and preschoolers with special needs. Upper Saddle River, NJ: Pearson, Merrill, Prentice Hall Publishing Co.

Meisels, S. (March, 2006). Accountability in early childhood: No easy answers. Occasional Paper, 6. Chicago: Erikson Institute, Herr Research Center for Children and Social Policy.

Neisworth, J. & Bagnato, S. (2005) DEC Recommended Practices: Assessment. In S. Sandall, M. L. Hemmeter, B. Smith, & M. McLean (Eds.), DEC recommended practices: A comprehensive guide. Longmont, CO: Sopris West.

Rasch, G. (1960). Probabilistic models for some intelligence and attainment tests. Chicago: University of Chicago Press.

Rasch, G. (1966). An item analysis which takes individual differences into account. British Journal of Mathematical and Statistical Psychology, 19, 49-57.

Snyder, S. & Sheehan, R. (1992). The Rasch measurement model: An introduction. Journal of Early Intervention, 16(1), 87-95.

Thompson, S., Johnstone, C.J., & Thurlow, M.L. (2002). Universal design applied to large scale assessments. Minneapolis, MN: University of Minnesota, National Center on Educational Outcomes.

Wilson, M. (2005). Constructing measures: An item response modeling approach. Mahwah, NJ: Erlbaum.

 

Top

---

CALCULATING ABILITY SCORES

Ability scores are estimated for each child for each Indicator Group by creating a total raw score for the Indicator Group. The total raw score is the sum of the ratings of all Measures within an Indicator Group. The figure below shows a DRDP access Rating Record with each of the Motor measures completed. By summing each of these ratings we get a total raw score of 19 for the Motor Indicator.

Completed Rating Record for the Indicator Group Motor.

CALCULATING SCALE SCORES

To derive scale scores, raw scores are transformed into logits (short for “log-odds units” or logarithm of odds units) using a simple mathematical procedure. The transformation requires that the raw score be converted into a proportion by dividing the total raw score by the highest possible raw score for the Indicator Group. See below for an example of how to calculate the raw score proportion.

Example of how to calculate the raw score proportion.

Measure	Observed rating from Figure 4	Highest Possible Rating
Movement	5	9
Balance	5	9
Grasp/Release and Manipulation	5	9
Eye-Hand Coordination	4	9
Total	19	36

Raw score proportion = (19/36) = .53

CALCULATING LOGITS

Logits are calculated by taking the natural log of the odds of correctly responding to the item.

The table below shows the calculation of logits for three different children.

	Observed Ratings			Maximum rating for measure
Movement	Child A	Child B	Child C	9
	1	5	8
Balance	1	6	8	9
Grasp/Release and Manipulation	1	6	9	9
Eye-Hand Coordination	2	5	8	9
Total raw score	5	22	33	36
After calculating the total raw score for each child, calculate the proportion of the maximum rating for the measure represented by his or her total raw score. Equation: Proportion of maximum rating for the indicator = total raw score/maximum rating for the indicator Numerical example (Child A): 5/36 = .14
Proportion of maximum rating for Indicator	Child A	Child B	Child C
	0.14	0.61	0.92
Next calculate the inverse of that proportion. Equation: Inverse proportion = 1 – proportion of maximum rating for the indicator Numerical example (Child A): 1 - .14 = .86
Inverse proportion	Child A	Child B	Child C
	0.86	0.39	0.08
Next calculate the odds of the proportion. Equation: Odds of success = proportion of maximum rating for the indicator/inverse proportion Numerical example (Child A): .14/.86 = .16
Odds	Child A	Child B	Child C
	0.16	1.57	11.00
Next calculate the natural logarithm of the odds Equation: Natural Log (Odds) Numerical Example (Child A): LN(.16) = -1.82
log odds (logits)	Child A	Child B	Child C
	-1.82	0.45	2.40

 

Top

---

Glossary

Term	Definition
Ability score	Ability scores are estimations of child ability, which are obtained by adding the raw scores for each Measure in an Indicator Group. The resultant total raw scores are then transformed into an equal-interval scale from 100 to 300.
Age-matched typically developing children	Age-matched typically developing children were drawn from a representative sample of children in state-funded preschools who were administered either the DRDP access or the PS DRDP-R. From this sample the mean and standard deviation were calculated for three age groups (3, 4, and 5) for each instrument. 1.3 standard deviations below the mean was used to define the zone of typical development for the Developmental Status Reports.
Authentic assessment	Authentic assessment is assessment of children while they are engaged in real-life tasks in typical environments. Typically this assessment is based on observation rather than a structured assessment situation.
Calibration	Calibration is the process of determining the relation between the output of a measurement instrument and the value of the attribute it is measuring. Calibration links the hypothesized developmental continuum for a Measure of the DRDP access to resultant scores.
Construct map	A construct map is a diagram of the levels of the developmental continuum which makes up a Measure on the DRDP access.
Developmental construct	A construct is a theoretical entity or dimension. A developmental construct is a theoretical entity or dimension that describes child development. Each Measure on the DRDP access is designed to measure child progress on a developmental construct.
Developmental Status Reports	A Developmental Status Report is a summary of a child’s scores for one administration of the DRDP access produced by the web-based software used to report data to the California Department of Education. The scores are summarized by Indicator Groups. For each Indicator Group a scale score, the typically developing range for age-matched peers, and a developmental ruler are presented.
Indicator	An Indicator is a specific measurable dimension of a Desired Result. Each Indicator is made up of Measures.
Indicator Group	Data from the DRDP access is reported by Indicator Group. The ten Indicators of the DRDP access are grouped for reporting scores into eight Indicator Groups. The Self- Concept and Social/ Interpersonal Skills Indicators have been combined, and Learning and Cognitive Competence Indicators have been combined, resulting in eight Indicator Groups.
Logarithm	A logarithm is a mathematical operation and is the power to which a base number must be raised to yield a given number. Logarithms are typically calculated in base 10. Logarithms are the opposite of exponents in a way that is similar to division being the opposite of multiplication. For example the logarithm of 10 is 1 since 101 = 10. The logarithm of 100 is 2 since 102 = 100. The logarithm of 1000 is 3 since 103 = 1000.
Logits (short for “logs-odds units”)	Logits are scaled units that are equally spaced along a developmental continuum.
Mastery	Mastery is the criteria for rating a developmental level on the Measures of the DRDP access. For a child to have mastered a particular level, the child must typically demonstrate the behavior easily and confidently, consistently overtime and in different settings.
Measure	A Measure is the developmental continuum along which a child’s observed behavior is assessed on the DRDP access. Each Indicator is made up of several Measures and each Measure covers one developmental construct within the Indicator.
Natural logarithm	The natural logarithm is calculated in base “e” and is a number that frequently occurs in the natural world. e is an irrational number that can be rounded to 2.718. The natural logarithm is calculated using the same method as the base 10 logarithm but with a different base. For example the natural logarithm of e is 1 since e1 = e. The natural logarithm of 7.38 = 2 since e2 = 7.38. The natural logarithm of 20.09 = 3 since e3 = 20.09.
Odds of the proportion	An odds ratio is a mathematical quantity that describes the probability of success for an outcome. For the DRDP access, the “outcome” is mastery of an Indicator Group. When the odds are nonnegative with a value greater than 1 success on the outcome is more likely than failure. When the odds are negative with a value less than negative 1 then failure is more likely than success on the outcome (Agresti, 1996).
Probability theory	Probability theory is a set of mathematical equations used to define the chance of events occurring.
Scale scores	Scale Scores are raw scores that are transformed so that equal intervals are maintained between each unit on the scale. For the DRDP instruments, the mean of each Indictor Group is 200 and the range is from 100-300. Children’s scores will be reported in units of 1 on either side of the mean. Scale scores allow a comparison of developmental status across Indicators and time.
SEDRS	SEDRS is the Special Education Desired Results System. It is a web based data entry system developed by CDE for entering Desired Results data for preschool children with IEPs.
Total raw score	The total raw score is the sum of the ratings of all measures within an Indicator group.

 

Top

---

 

Understanding the DRDP access Measurement Model was developed by the Desired Results access Project to support the implementation of the Desired Results Developmental Profile Assessment System based on the guidelines and specifications of the Special Education Division. This document has been produced under a contract between the California Department of Education, Special Education Division and the Desired Results access Project, A Special Project of the Napa County Office of Education.

© 2008 The Desired Results access Project, Napa County Office of Education
All rights reserved
Permission to reproduce for instructional purposes

The Desired Results access Project — A Special Project of the Napa County Office of Education is funded by the California Department of Education (CDE), Special Education Division (Contract #CN077059), to assist CDE with developing and putting in place a system to assess the progress of California’s preschool children with disabilities.

Download printable PDF of this page (2.15mb)

 

Updated 01/31/08