MJ 0010 – Communication Research
Q. Write a long note on choosing measures.
A. No matter what is the design of your research, your study will involve measuring the values of the variables included the design. There are many ways in which a giver variable can be measured. So, let us go through several important characteristics of a measure.
a. Assessing validity: We have already discussed the concepts of the internal and the external validity, which are attributes of research design. Here we will discuss other forms of validity that applies to measure. The validity of the measure is the extent to which it measure the thing to you want to measure. Imagine, for eg, that you decide to measure a person’s general intelligence by placing a tape measure around that person’s skull at the level of his / her forehead, on the theory that larger skulls house larger brains produce higher intelligence. In this case tape measures is a valid measure of length but actually is it a valid measure intelligence? No, because measures of skull and brain size turned out to be unrelated to intelligence and it was later found that the largest brains on record belonged to retarded person. Thus measures of intelligence based on skull or brain sizes turn out to be valid. b. Demonstrating Reliability and Accuracy: The reliability of a measure concerns its ability to produce similar results when repeated measurements are made under identical condition. The term accuracy means a measure that produces results that agree with a known standard. A particular measuring instrument can be inaccurate but reliable, but the converse is not true. It cannot be unreliable but true. For eg; a thermometer whose glass has slipped down in its bracket may read 21% each time it is immersed in water under ice water. But as it gives same reading every time in the same conditions, it is reliable. If the thermometer reading does not agree with a known standard, as it is reliable, it cannot be accurate. c. Scale of measurement: Scales of measurement refers to the units in which a variable is measured, centimeters, seconds, 10 points and so on. Stevens identified four basic scales. From least to the most information they give, these are: Nominal scales
Q. What is sampling. Discuss in detail.
A. Sampling is widely used in mass media research. Surveys are the important part in research studies and form a distinct discipline in itself. Nationwide surveys require a consultation of technical discussion of sampling.
Population and Sampling: Research areas can be investigated using human beings. When your research topic has to be verified y the investigation of human interest then you are require population under study. But it is impossible to study entire population, so it is easy to select a small sub-group from the larger should be able to give relevant information regarding your research topic. It has to be selected on the basis of importance and not availability. Generalization: Your goal as a researcher is to apply the results of your experiment to the larger population from which the sample was drawn. You should not apply your results to those subjects only who participated in the study. Applying findings from a sample to a larger population is known as generalization. As the results of an experiment are to generalize the population, so we must be very careful while selecting the sample. The optimal procedure is to identify the population and then draw a random sample of individuals for participation in the experiment. In random sampling, every person in the population must be eligible for population. They also should get an equal chance for being chosen. Random sampling is constructed by placing the name of every potential participant and then drawing out a specified number of names at one time. But in practice, this is not. Usually college students are used as they are easily available. The...
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