Steps in validating research instruments
Measurement consists of assigning numbers or labels to the units of analysis that accurately represent their position on the variables under study.
For example, if a research study is examining Maths achievement of JS1 students, each unit of analysis (JS1 student) must be assigned a number that represents their position in Maths achievement.
The second step in measurement is to develop a construct definition of each of the key variables.
The construct definition is the theoretical definition, and this definition is best obtained by referencing other research studies that have measured the same variable.
For more information on manipulating variables, go to Step 11: Manipulate the Treatment.
As can be seen from the figure above, once the research design has been determined, then the researcher has two separate responsibilities: identifying the sample and determining how the key variables will be measured.The abstract construct definition of socioeconomic status provides no information about how to measure socioeconomic status.Therefore, the researcher needs to think of how to make that definition more concrete, or how it will be practically measured, a process called operationalize.The process of measurement consists of moving from the theoretical definition of a variable (typically called the construct definition) to the concrete mode of measuring that variable in the research study.Measurement is typically done by developing an instrument, which can be a questionnaire, an examination, an interview, an observation schedule, etc.