An Introduction to Evaluation by Chris Fox Robert Grimm Rute Caldeira

Author:Chris Fox, Robert Grimm, Rute Caldeira [Chris Fox, Robert Grimm, Rute Caldeira]
Language: eng
Format: epub
Tags: Social Science, Research, Reference
ISBN: 9781473987807
Google: VtPUDAAAQBAJ
Publisher: SAGE
Published: 2016-10-18T03:37:33+00:00

To produce robust evidence, research instruments have to be reliable. A measurement is reliable if it produces consistent results under similar conditions.

Sampling

The collection of individuals researchers are interested in is called the target population or the theoretical population. To produce valid and reliable observations, the target population has to be clearly defined and well distinguished from other population groups. Evaluators should always report the definition of the target population including age, gender, geographic area, etc. Exclusion of specific subgroups should also be mentioned in the evaluation report.

It is for the target group that researchers wish to make generalisable statements. Some studies conduct a census of the target population. A census collects data from every member of the target population. In most cases, a census is not a practical solution because the target population is too big. In these situations, studying a sample of the target population is a sensible alternative.

Sampling refers to the systematic process of selecting cases from a target population such that each sampled unit has a known chance of selection. A robust sampling strategy enables researchers to make generalisable claims by studying only a selection of the target population. Generalisable statements can only be made if the sample is representative of the target population. Therefore, the sample has to share all the key characteristics of the population it seeks to represent.

We can broadly distinguish between two approaches to sampling: probability sampling and non-probability sampling.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.