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Research: Instruments & Sampling

1-What are some examples of a reliable instrument? A valid one?

Can you identify an instrument that is reliable but not valid?

Valid but not reliable?

2-What description/requirements would we establish for measuring the height of a sample of people? Assume that different researchers will be doing the work at different locations.

3-What are the four data scales? Give an example of each

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The response address the queries posted in 848 words with references.
//First of all, we will discuss the meaning of 'Reliable Instruments'. We will also discuss the tools, which are reliable in a research. After it, we will discuss the valid instruments and also the meaning of 'Valid Instruments'.


Reliable Instruments

A reliable research instrument is a one which gets the same results on repeated trials. Instrument reliability is related with the tendency of maintaining consistency determined on the basis of repeated measurements (Key, 1997). Out of all the research instruments, only mechanical instruments which are used for primary data collection are considered to be reliable. The prominent examples of these reliable mechanical instruments are tachistoscopes and galvanometers.

Galvanometers measure the responses obtained on various parameters such as emotions, interest in an advertisement or a picture, etc. Tachistoscopes are the instruments where a message is flashed for about one hundredth of a second, several times and the subject's behavior is observed.

Valid Instrument

Validity defines a measurement for the research. For a research, validity can be measured in terms of content, construct and criterion of the study. The research instruments which possess all these elements are valid like questionnaires (Key, 1997).

//Above we discussed the reliable and the valid instruments. Now, we will discuss the ...

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The response addresses the queries posted in 690 Words, APA References.