Perspectives for Interpretation

1. Perspectives for Interpretation • Clinical (facilitators/inhibitors): • What’s easy/difficult for the student • Observable behaviors and reactions • Background information • Classroom observations • Projective assessments • Rating scales/interviews/checklists • Instructional or developmental zones

2. Perspectives for Interpretation (Cont.) • Statistical: • Inter-test comparisons • Intra-test comparisons • Numerical Analysis • Standard scores • Percentile ranks • SD Difference scores/z scores • Discrepancy analysis

3. Perspectives for Interpretation (Cont.) • Confirmation/Discovery – Implications • What has been confirmed? • What new information has been revealed? • What are the implications of confirmed or new information? • What instructional/educational recommendations can be generated? • What (if any) unresolved questions/issues remain?

4. Perspectives for Interpretation (Cont.) • Procedural/Eligibility: • Is there a clinically determined disability(ies)? • If “yes” – what is it and what is the data that supports it? • If “no” – what do you do the with data, implications, and educational recommendations generated thus far? • Is there a need for specialized instruction?

5. LEVELS OF INTERPRETIVE INFORMATION • Qualitative: observations, task analysis, response analysis, • Developmental: linear scale – how much has been attained. • Proficiency: quality of performance relative to criterion demands • Statistical Standing: position relative to peer group or predicted score.

6. Essential Terminology • Broad Abilities - constructs • Narrow Abilities – elements within constructs • Domain General • Domain Specific • “Clean” measures/“Mixed” measures • Rate tests • Power tests • Rate and Power tests

7. Developmental Scores: What do Age and Grade Equivalents Really Tell Us? Synonym for a raw score. Mean age/grade of individuals in norming sample who obtained that raw score. Should be understood in the context of the developmental zone around each score.

8. Proficiency Statements:Developmental/Instructional Zones • A more effective way of reporting age/grade equivalent information. • Permits a view of the growth curves for specific abilities and skills; provides instructional insights about what is easy or difficult for a student.

9. Proficiency Scores (Cont.) • Basic Interpersonal Communication Skills (BICS) & Cognitive & Academic Language Proficiency (CALP) scores: These describe elements of language proficiency on a qualitative scale from “negligible” to “proficient” to “advanced”. • Relative Proficiency Index Score (RPI score): This score presents a ratio of mastery/proficiency relative to what is considered as “typical proficiency” (90% proficiency) needed in a given skill or ability at a specific age/grade level. NOT WHAT PEERS ARE DOING – RATHER IT’S WHAT IS NECESSARY AT A SPECIFIC AGE OR GRADE LEVEL.

10. Cookie-Jar Proficiency Analogy Reading Comprehension – 2nd grade level subskills necessary to do grade level tasks with “typical” proficiency. If “typical” proficiency means having the 6 subskills (6 cookies in the jar) necessary to demonstrate 90% effectiveness in the curriculum then 90/90 signifies an equivalent level of success relative to what is demanded at that grade level (i.e. you’ve got as many cookies as you typically need or adequate “cookie-ness”)

11. Cookie-Jar Proficiency Analogy Suppose you only have 3 out of the 6 subskills (only 3 cookies when you needed 6). What is your Relative Proficiency compared to what is typically demanded of you in the curriculum? 45/90 You’re only likely to be half as effective on typical demands in that skill at that grade level (or you’re lacking cookies or have limited “cookie-ness”).

12. Cookie-Jar Proficiency Analogy Suppose you have 9 skills but you typically only need 6 (more cookies in the jar than is typically necessary). What is your Relative Proficiency compared to what is typically demanded of you in the curriculum? 96/90 You’re likely to find typical demands in that skill at that grade level to be very easy (abundant cookie-ness)

13. Cookie-Jar Proficiency Analogy • Reading Comprehension – 10th grade level subskills necessary to do grade level tasks with “typical” proficiency . Now “typical” proficiency means having the 16 subskills mastered in order to demonstrate a 90% level of effectiveness in the curriculum. A 90/90 in the skill at 10th grade presumes that a greater amount of subskills have been acquired than were necessary for 2nd grade level effectiveness.

14. Cookie-Jar Proficiency Analogy Reading Comprehension – 10th grade level – 16 subskills necessary to do grade level tasks with “typical” proficiency. Now what is a 45/90 expressing? If you need 16 subskills for “typical” proficiency but you only have acquired 8, you are likely to be only half as effective in that curriculum level. Notice that a 45/90 is expressing the likely proficiency relative to what is typical for competency at this higher grade level. You still have collected more skills than at 2nd grade level. The “90” is a moving target – it is relative to the demands at a given age or grade level.

15. Statistical Scores:Standard Scores, Percentile Ranks, z scores • Statistical metrics present a normative ranking to peers or to one’s self. They are NOT quality-of- performance indicators. • Statistical scores take on clinical relevance when they are linked to information related to proficiency and behavior. • Because they are mathematically sound they are often utilized for very making inter-test comparisons and decisions that rely on the identification of a specific number of people (e.g., eligibility for special education).

16. Statistical Perspectives • Me to You – comparison to others of my age (AGE NORMS). • Me to You – comparison to other in my grade (GRADE NORMS). • Me to Me – comparison of my performance to a predicted score (DISCREPANCY NORMS).

17. Guide to Statistical Significance for z Scores • -/+ SD values ranging from around 1.25 to 1.39 are statistically "mild" amounts of difference (from the 8th to the 10th %ile, or the 92nd to the 90th percentile) • -/+ SD values ranging from around 1.40 to 1.69 are statistically "moderate" amounts of difference (from the 4th to the 7th %ile) • -/+ SD values at or greater than 1.70 are generally representing statistically "significant" amounts of difference (a discrepancy percentile rank of < 3 or > 97) Always determine if statistical significance is pragmatically or educationally significant for the student.

18. Descriptors for Standard Scores • There is a generic range for standard scores and percentile ranks based upon accepted statistical guidelines: • 90 – 110 is average • 80 – 89 is low average • 70 – 79 is below average or low • Below 70 is very low • 111 – 120 is high average • 121 – 130 is superior • Above 130 is very superior

19. Descriptions of Standard Scores (Continued) • Carefully review the guidelines presented in each test manual including the case study reports. Understand that descriptors within examiners manuals are guidelines and suggestions. • When different instruments present disparate descriptors for the same standard score ranges, it can be confusing and misleading to the reader. Anticipate and be prepared to address these inconsistencies in the written evaluation report. • Decide how and if to use descriptors -- alwaysexplain the apparent discrepancies between descriptors when the numerical/statistical presentation between two tests is the same.

20. Developmental Zone or Instructional Zone • Easy (RPI=96/90) to difficult (RPI=75/90) range • Length of band reflects rate of growth • Wide = period of development with little growth • Narrow = period of development when growth is rapid 6.5 2.3 >14.5 K.6 K.3 1.1 Age or Grade Profiles

21. SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 If confidence bands overlap, assume no significant difference exists. Standard Score/Percentile Rank Profiles • Range of scores that contain subject’s true score at a 68% level of confidence (+/- 1 SEM) • Evaluate significance of difference between any 2 tests of clusters (statistical probability statements)

22. If separation between bands is less than the width of the wider band, assume a possible statistical difference exists. SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 If separation between bands is greater than the width of the wider band, assume a significant difference exists.

23. SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 SS <40 40 50 60 70 80 90 100 110 120 130 140 150 160 >160 Oral Lang. PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 PR <0.1 .1 .5 1 2 5 7 10 15 20 30 40 50 60 70 80 85 90 93 95 98 99 99.5 99.9 >99.9 List. Comp. B. Reading B. Math B. W. Lang. Basic RS Basic WS Average