Understanding your data
Interpreting CoPS data is a complex and varied process, and there is not necessarily one correct way to do it. A careful, problem-solving approach is necessary. Teachers should resist the temptation to seek instant answers but instead should get used to considered a number of essential issues before reaching a conclusion. It is important not to lose sight of the fact that the interpretation (particularly in the case of the ‘at risk’ student) is likely to have a significant impact on the student’s education, and such decisions should not be made lightly or hurriedly.
For each CoPS subtest, results are calculated automatically and are shown both for accuracy (black dots on the report) and speed (blue dots on the report). Of these, accuracy is usually the most important indicator.
CoPS results for both accuracy and speed on each subtest are given Standard Age Scores (SAS). SAS, like IQ, are usually expressed with a mean of 100 and a standard deviation of 15. These scores reflect the student’s performance compared to those of the norm referenced group, which is based on the student’s age, in three-month age bands from 4:0 up to 7:11.
Any test score is only an estimate of the student’s ability, based on their performance on a particular day. Performance on any test can be affected by several factors. The CoPS report provides confidence bands, which give an indication of the range within which a student’s SAS score lies.
The dot on each subtest row within the table represents the student’s SAS and the horizontal line represents the 90% confidence band. The shaded area shows the average score range. 90% confidence bands are a very high-level estimate; if the test were taken again, we would expect the score to fall within this range 90% of the time.
How low must a CoPS subtest result be before the teacher should be concerned about the student’s performance? Put another way: what is the critical cut-off point or threshold that can be used when deciding whether or not a given student is ‘at risk’? Unfortunately, this is not a question that can be answered in a straightforward fashion, because much depends on other factors. These include: (a) the particular CoPS subtest under consideration (some subtests are more highly predictive of later literacy difficulties than others), (b) whether the results of other CoPS subtests confirm or disconfirm the result being examined, and (c) the age of the student being tested.
The threshold of concern
Traditionally, a score which falls below an SAS of 85 (which is below one standard deviation below the mean) is by definition significantly below average and thus indicates an area of weakness, which requires some intervention. However, as stated at the start of this chapter, any test score is only an estimate of the student’s ability, based on their performance on a particular day. As there is some error in any test score, those test scores in the borderline range (i.e. just above SAS 85) could potentially represent ‘true scores’ that are within the ‘at risk’ range.
Therefore, the CoPS report identifies SAS scores of 88–94 as being ‘Slightly below average’ and SAS scores of 75–87 as ‘Below average’. As such, action is recommended where SAS scores are in either of these ranges and the CoPS report will refer the tester to the Indications for Action table on the Downloads page, where appropriate. Where there is strong confirmation (e.g. a number of related subtests below an SAS of 88) then the assessor can be convinced that concern is appropriate.
The threshold of risk
On the other hand, where a student is scoring below a Standard Age Score of 75 on any subtest (near or below two standard deviations below the mean), this generally indicates a serious difficulty and should always be treated as diagnostically significant. Usually this will be a strong indication that a student is at risk of later literacy and/or numeracy difficulties. Remediation by way of training will often be required as well as a differentiated approach to basic skills teaching. The CoPS report identifies SAS scores below 75 as being ‘Very low’ and will refer the tester to the Indications for Action table on the GL website. Again, where there is strong confirmation (e.g. a number of related subtests below SAS 75) then the assessor can be even more confident about the diagnosis.
Low overall profile
High overall profile
Many CoPS reports display a complex pattern of ‘highs’ and ‘lows’ and at first sight appear quite puzzling.
For an explanation of complex overall profiles and to see 2 relevant case studies, please click here.
It is recommended that you consult the User Manual found in the Downloads Section as it contains comprehensive exploration of data profiles, and advice on interpretation.
This includes case by case examples and a breakdown of results from the phonological subtests, auditory memory subtests, and visual memory subtests.