Chapter 7

Instrumentation

Empirical Data• We need DATA

• We can’t rely solely upon our senses

• We develop INSTRUMENTS to compensate for the limitations of our senses.

Good Instrumentation• Validity and Reliability

• Validity is the confidence we have that we are measuring what we think we are measuring

• Validity is the degree to which you can defend the conclusions you draw from using the instrument

Reliability• Consistency

– If the instrument is used twice in the same situation with the same person, will it produce the same results?

– Can we rely upon it to be consistent time after time? (think of a watch as instrument to measure time)

Reference point of data collection

• Who provides the data?– Researcher – checklists, observations– Participant – self report– Third party – checklists, observations

Researcher completed

• Checklists

• Interview schedules

• Notes of observations

Participant Completed• Questionnaires

• Performance tests

• Personality tests

• Projective tests

• Achievement tests

• Aptitude tests

• Aptitude Tests– Predict future performance

• Achievement tests– Measure current knowledge

• Performance tests– Measure current ability to complete tasks

• Norm-referenced tests– Comparison of individual score to others– Intelligence test– ISAT, Iowa Basic Skills Test– SAT aptitude test– Personality test

– Percentile’s - derived scores– Grading on a curve

• Criterion referenced test– Individual score is compare to a benchmark (a

criterion)

– If Raw Score used (no conversion): C-R test– Mastery of material– Earning a grade in my class

– Disadvantage is potential lack of variability

• End chapter 7