Reliability

• Results are replicable- consistent results on multiple administrations

• Types of Reliability

  • Test-retest- a tests stability over time

  • Split-half- tests internal consistency

  • Rater- level of agreement among individual rating the test

    • Two types:

      • Intrarater: if results are consistent when the same person rates the test on multiple occasions

      • Interrater: if results are consistent when more than one person rates the test

Alternate form or Parallel form- the test’s correlation coefficient with a similar test

Validity

• The test measures what is claims to measure

• Types of Validity

  • Face- test looks like it assesses the skill it assesses

  • Content- test’s contents are representative of the content domain of the skill being assessed

  • Construct- the test measures the theoretical construct it claims to measure

  • Criterion- test is related to an external criterion in a predictive or congruent way

    • Two types:

      • Concurrent: test compares to an established standard

Predictive: the test predicts performance in another situation or in the future

Shipley, K. G., & McAfee, J. G. (2016)

Measures of Central Tendency

All considered an example of an average point, So is there a difference?

Mean: The mean takes all data and divides it by the amount of data contributed to get an average point (i.e. 2, 3, 4, 6, 6; mean is 4.2)

Median: Is the middle number of all data points when lined up in order from smallest to largest. (i.e. 2, 3, 4, 6, 6; the median is 4)

Mode: Is the most frequent data found in a data set. Useful with a numeric or non-numeric representation (i.e. 3, 4, 6, 6, 2; the mode is 6 or blue, blue, orange; the mode is blue).