How do you calculate reliability using Kuder-Richardson?

How do you calculate reliability using Kuder-Richardson?

Kuder-Richardson Formula 20 (Definition & Example)

  1. The Kuder-Richardson Formula 20, often abbreviated KR-20, is used to measure the internal consistency reliability of a test in which each question only has two answers: right or wrong.
  2. The Kuder-Richardson Formula 20 is as follows:
  3. KR-20 = (k / (k-1)) * (1 – Σpjqj / σ2)

How do you read a KR-20?

KR-20 scores range from 0-1 (although it is possible to obtain a negative score); 0 indicates no reliability and 1 represents perfect test reliability. A KR-20 score above 0.70 is generally considered to represent a reasonable level of internal consistency reliability.

How do you use a KR-20?

The steps for conducting Kudar-Richardson 20 (KR-20)

  1. The data is entered in a within-subjects fashion.
  2. Click Analyze.
  3. Drag the cursor over the Scale drop-down menu.
  4. Click on Reliability Analysis.
  5. Click on the first dichotomous categorical item to highlight it.
  6. Click on the arrow to move the item into the Items: box.

What is Kuder Richardson test?

Kuder-Richardson Formula 20, or KR-20, is a measure reliability for a test with binary variables (i.e. answers that are right or wrong). The KR20 is used for items that have varying difficulty. For example, some items might be very easy, others more challenging.

How do you use Kuder Richardson formula 21?

Kuder-Richardson Formula 21 (KR-21) Similarly to KR-20, K is equal to the number of items. Difficulty level of the items (p), is assumed to be the same for each item, however, in practice, KR-21 can be applied by finding the average item difficulty across the entirety of the test.

What is a good KR-20?

Essentially the KR-20 is assessing how consistent the results from the test are, or how well the test is measuring what you want it to measure. A KR-20 score above 0.70 is generally considered to represent a reasonable level of internal consistency reliability.

What is a good Kuder Richardson score?

The closer the score is to 1, the more reliable the test. Just what constitites an “acceptable” KR-20 score depends on the type of test. In general, a score of above . 5 is usually considered reasonable.