Assessment of Students with Special Education

Needs

SPE 3374Margaret Gessler Werts124D Edwin Duncan Hall

262 6365www1.appstate.edu/

~wertsmg

• What is a child with special needs?

• Why do we spend so much time trying to identify one when most people can spot one at a distance?

Assessment

• Why does your teacher assess you and your work?

• What does the assessment have to do with what you know?

• Which assessments are useful and which are not?

• Of what use are tests in any class?

• Of what use is the Praxis?

• What purpose does the Praxis and other standardized tests have for the test interpreters?

Overall Purpose of assessment:

Gathers information to assist in decision making 1.     Screening

To determine whether there is a reason or suspicion that there is a reason for continued testing.

 (Why wouldn’t we just test anyway?)

• 2.      Monitoring students' progress. Assessing students formatively allows the teacher the opportunity to determine whether or not a student is making adequate progress toward desired instructional outcomes.

• 3.      Assigning grades or ranks. Assessing students provides the teacher with at least one type of evidence to assist in assigning grades.

• 4.      Determining one's own instructional effectiveness. Assessing students can provide teachers with information related to teaching effectiveness. If students are achieving the desired instructional outcomes, then teaching is likely, although not definitely, effective.

• 5.      Influencing public perceptions of educational effectiveness. Students' scores on standardized achievement tests and statewide assessments are often used to inform the public as to the effectiveness of schools and teachers.

• 6. Clarifying teachers' instructional intentions.

• What a teacher intends on assessing influences what is taught, and vice versa. Also, national and statewide assessments often feedback to influence a state's, school's, or teacher's curriculum.

Definition: • Educational assessment is the

systematic process of gathering educationally relevant information to make legal and instructional decisions about the provision of services.

Assessment should:

• 1.     Relate to regular performance• 2.     Gather from interdisciplinary

sources• 3.     Consider all aspects of the

student's life

Basic terms

  Assessment: A general term used to denote the systematic collection and interpretation of data that is to be used in the making of educational decisions, including enhancing instruction.

More terms    Measurement: The explicit quantification

of the results obtained through testing that is designed to determine the degree of presence or absence of a particular characteristic, quality, or feature.

Test: An instrument or formal process that presents tasks that yields a specific type of measurement.

More terms

Evaluation: The placing of value or interpretation of a measurement. Evaluation encompasses the inferences that are drawn from measurements

Types of Assessments

• Formal• Informal• Observations• Authentic

INFORMAL STRATEGIES.

• 1.     Observations.• 2.     Curriculum based

assessments.• 3.     Work sample analysis.• 4.     Portfolios.• 5.     Task analysis.• 6.     Inventories.

INFORMAL STRATEGIES.

• 7.     Criterion referenced tests.• 8.     Diagnostic teaching.• 9.     Checklists and rating

scales.• 10.            Interviews.• 11.            Rating scales.

                  FORMAL STRATEGIESNorm referenced tests- compare a

students performance to that of a comparable group

   Use limited to groups who are much like the norm group

Very explicit instructions

Two types: Achievement = ? Aptitude = ?

Uses a variety of score reporting types– Raw scores, standard scores,

percentiles, stanines, t scores, z scores, etc.

Formal tests

• Norm referenced tests- compare a students performance to that of a comparable group.

• 1.     group.• 2.     individual.• Use limited to groups who are

much like the norm group.

Characteristics of formal tests

• Very explicit instructions.• Uses a variety of score reporting

types.• Scores are comparable to other

scores• Some scores are better for this use

than others

How do we know if a test is good for our purposes?

• Look at the norming sample.• Look at the validity.• Look at the reliability.• Look at the standard error of

measure.

• Where do we find this information?

The Examiner’s Manual

• The manual is your best friend!• It contains:

– Information about the concepts to be tested.

– Administration procedures (who should give it, basic test procedures, times, basals and ceilings).

Manual (con’t.) Specific subtest administration instructions

Script to readHow to score (usually with examples)Explanations of reasons for the scoring

Examiner qualifications– How much training– How much practice

• How to encourage and praise• Time needed

Manual (con’t).

How to calculate the age of a subjectHow to record the subtest raw

scoresHow to compute composite scoresTables for computing scoresHow to complete the graphics for

interpretation

Administering items

• Some tests require that you administer all items

• Some have ranges of items that you administer

• The appropriate point to start is usually given in the test manual.

Basals

• A basal score is the point at which it may be assumed that all lower items would be scored as correct

• The student establishes a basal by responding correctly to a predetermined number of items

Ceilings

• The point at which it may be assumed that all harder items will be scored as incorrect

• Student establishes a ceiling by responding incorrectly to a predetermined number of items.

ScoresThe assignment of a number or level to

an attribute or characteristic of a person.

• Raw scores.– Number right and number wrong

• Obtained Score: The score (measurement) that a student receives as a result of completing a particular test.

Derived scores: Scores that are weighted or otherwise standardized.

• Standard scores.– Those that have been transformed by

statistics

• Standard deviation.– How far a randomly drawn score will

be from the mean

More Scores

• Z scores– Mean 0

• T scores– Mean 50

• Percentiles– Rank of people

• Stanines– Standard nines

Error Score

The portion of a student's obtained score that is due to factors not associated with the student's actual level of achievement, such as guessing, poorly written questions, tiredness, and motivation.

Systematic Errors

Systematic errors consistently raise or lower the obtained score for all (or most) of those tested, (e.g., faulty testing procedures, questions that give away the answer, misunderstanding the directions

Random Errors

Random errors are the unpredictable sources of error that cause fluctuations in students' scores that are generally beyond the assessor's control, such as student fatigue, guessing, and motivation. We refer to these errors as "bad spaghetti days in the cafeteria."

True Score

A true score is a score that is free from error and accurately conveys a student's true level of achievement. In practice, a true score is the hypothetical average resulting from taking the same test repeatedly. There is a minimal chance of ever achieving a true score and is minimal chance that you will know which score is a true score.

Validity

The accuracy and appropriateness of the interpretations and inferences (evaluation) drawn from the results of a test. "Does this instrument measure what it says it does?"

Absence-of-Bias

• The absence of any characteristic associated with an assessment that might offend or unfairly penalize those being assessed and thus distort (depress or inflate) a student's score. "Does this instrument provide this examinee with a fair chance?"

Reliability

The consistency of results (measurement) obtained from an assessment, based on the control, reduction, and/or elimination of measurement error. "Does this instrument measure the construct resulting similarly over time, parts of the test, administrators, etc.?"

Measuring Reliability (Reliability Coefficients).

1.Measuring Stability.•         Test-Retest: a correlation

between two successive measurements using the same test.

2. Measuring Alternate-Form.•       Alternate Form: a correlation

between two successive measurements using two parallel forms of the same test.

       Inter-rater: a correlation between two persons rating the same performance using the same scoring criteria.

3. Measuring Internal Consistency.

        Split Half: a correlation between two halves of a test, obtained by dividing the test into two equal halves (e.g., odd questions vs. even questions).

Types of Reliability.

1.Stability: The consistency of test scores across different testing instances, using the same test. (i.e., consistency over time).

2.Alternate-Form: The consistency of test scores when comparing two supposedly equal forms of a test (i.e., consistency between tests).

3.Internal Consistency: The extent to which test items function consistently, assessing the same construct (i.e., consistency within a test).

Standard Error of Measurement.

• An estimate of the amount of error in a test score. The SEM is the standard deviation of the errors obtained in a series of measurements and is derived from the reliability coefficient. That is, how much can one expect a score to vary if the test were given again.

• where s = standard deviation of the test scores and r = reliability coefficient of the test.

• Since obtained scores contain error, the SEM can be used to construct confidence intervals or set "reasonable limits" on score interpretation regarding a student's true score. These intervals, or bands, are created by adding and subtracting the SEM to and from the individual's obtained score. That is, if a student has an obtained score of 80 on a test that has an SEM of 3.0, then the teacher can be confident that the student's true score is somewhere between 77 and 83.

• F. Estimating the Standard Error of Measurement (see Hopkins, 1998):

• Classroom teachers, most likely, will not know the SEM of the tests that they make. The SEM can be estimated given the number of questions that are asked, if each question on the quiz or test is worth 1 point. Remember, this is an estimate only.

• Using this method of adding and subtracting the SEM to and from the individual's score to determine "reasonable limits" is an effective way of determining whether two scores differ from each other in a meaningful way.

• For example, if Mica has an obtained score of 81 and Liza has an obtained score of 86, is that a real difference?

• But if we know that the SEM for the test that they took was 4.0 then Mica has a confidence band of 77 to 85, while Liza has a confidence band of 82 to 90. Since these bands represent the areas in which their true scores are likely to fall, and these bands overlap, the conclusion would be that their obtained scores of 81 and 86 are not meaningfully different.

• Obtained scores contain error. Combining the SEM and the normal curve can yield confidence intervals related to the true score.

• Approximately 68% of measurements fall between ± 1 standard deviations from the mean.

• Approximately 95% of measurements fall between ± 2 standard deviations from the mean.

• Approximately 99.7% of measurements fall between ± 3 standard deviations from the mean.

Thus, if Charles has an obtained score of 77 on a test with an SEM of 3.5 we can be

68% sure that his true score is between 73.5 and 80.5 (± 1 SD),

95% sure that his true score is between 70.0 and 84.0 (± 2 SD)

99.7% sure that his true score is between 66.5 and 87.5 (± 3 SD).

Differences between error assumptions

73.5

70

67.5

80.5

84

86.5

0 20 40 60 80 100

68%

95%

99%