Instrumentation

           Instrumentation

Written by Jack R. Fraenkel and Norman E. Wallen in How to Design and Evaluate Research in Education. McGraw-Hill.2009

A. INSTRUMENTATION
The term instrumentation refers to the entire process of collecting data in a research investigation.

B. WAYS TO CLASSIFY INSTRUMENTS
Research instruments can be classified in many ways. Some of the more common are in  terms  of  who  provides  the  data,  the  method  of  data  collection,  who  collects  the data, and what kind of response they require from the subjects. Research data are obtained by directly or indirectly assessing the subjects of a study. Self-report data are provided by the subjects of a study themselves. Informant data are provided by other people about the subjects of a study.

C. TYPES OF INSTRUMENTS
There are many types of researcher-completed instruments. Some of the more commonly  used  are  rating  scales,  interview  schedules,  observation  forms,  tally  sheets, flowcharts,  performance  checklists,  anecdotal  records,  and  time-and-motion  logs. Many types of instruments are completed by the subjects of a study rather than the researcher.  Some  of  the  more  commonly  used  of  this  type  are  questionnaires;  self-checklists;  attitude  scales;  personality  inventories;  achievement,  aptitude,  and  performance tests; and projective and sociometric devices.

The types of items or questions used in subject-completed instruments can take many forms, but they all can be classified as either selection or supply items. Examples of selection items include true-false items, multiple-choice items, matching items, and interpretive  exercises.  Examples  of  supply  items  include  short-answer  items  and essay questions. An excellent source for locating already available tests is the ERIC database. Unobtrusive measures require no intrusion into the normal course of affairs.

D. VALIDITY AND RELIABILITY
An  important  consideration  in  the  choice  of  a  research  instrument  is  validity:  the extent  to  which  results  from  it  permit  researchers  to  draw  warranted  conclusions about the characteristics of the individuals studied. A reliable instrument is one that gives consistent results.

E. OBJECTIVITY AND USABILITY
Whenever possible, researchers try to eliminate subjectivity from the judgments they make about the achievement, performance, or characteristics of subjects. An  important  consideration  for  any  researcher  in  choosing  or  designing  an  instrument is its ease of use.