1. Scoring: Measures of Central Tendency
There are three measures:
mean
median
mode

2. Mean Measurement of Scoring
most used method
Mean = average
Mean = the sum of all scores divide by the # of scores
affected by extreme scores
Often use for:
GPA ranking
Field goal Average

3. Median Measurement of Scoring
The middle score falls in the middle of the distribution; determines the 50th percentile
the score that splits the distribution in half
50% of scores are above median
50% of scores are below the median

4. Mode Measurement of Scoring
The score that occurs the most frequently.
Called the modal score
However you can sometimes get:
No mode
Bimodal - 2 scores that occur the same number of times
multimodal

5. Lets Look at Some Examples
Which scoring measurement is best to use?

6. Designing High-Quality Classroom Assessments
What is the Criteria for Ensuring High-Quality Classroom Assessments?

7. High-Quality Assessments need:
Clear and appropriate learning objectives
Alignment
Appropriateness of assessment method
Validity
Reliability
Fairness

8. What is Assessment Validity ?
Ask:
Does the test measure what it is suppose to measure?

9. A Score is Generated- Validity Coefficient
Validity Evidence
Determine the soundness of your interpretations and uses of the students’ assessment results
Uses statistical tools to test the results in order to determine the degree of confidence we can place on that test.
A Score is Generated- Validity Coefficient

10. What is Assessment Reliability?
Ask:
Does the test yield the same or similar score rankings consistently?

11. Reliable Evidence
Refers to the consistency with which it yields the same rank for individuals who take the test more than once
Example :
Step on a bathroom scale and take 5 weights over 1 hour. Measurements differ by 0.02
Is that scale Reliable?

12. What About These? 1st attempt 75 50 93 80 67 2nd Attempt 78 62 85 9766

13. Problems with Reliability
Students could have done better at guessing one time over the other
Some memory of the first test
How long of an interval between taking the tests? Too long vs. too short

14. Looking at Test Accuracy
Does the test score closely approximate an individual’s true level of ability, skill, or aptitude?

15. Accuracy and Testing Error
Tests make mistakes. All tests are associated with some degree of error.
No Test measures perfectly

16. Error in Testing
Error is any factor that leads an individual to perform better or worse on a test
Therefore: it is not a true measurement of their level of performance.