Question

Suppose you read a research article in which the study authors stated that they had collected a sample of 150 adolescents from a single city and found that 22 of them reported being in a gang. What is the population being studied here? What additional information would you need to know about this sample in order to decide whether to trust this finding as being truly reflective of that population? What characteristics would the sample need to have in order for it to be trustworthy?

Answer 1

(a)

The population being studied here : All adolescents from a single city

(b)

The characteristics that would the sample need to have in order for it to be trustworthy:

(i) The sample of 150 adolescents from a single city should truly represent the characteristics of the entire population: all adolescents from a single city. For this purpose, the sampling should not have any bias. Also the method of collection should be statistically appropriate.

(ii) The size of the sample: n = 150 adolescents should be adequate. i.e., neither too large nor too small as per statistical theory.

(iii) The sample should be homogeneous in nature.

(iv) The sample items should be independent of each other. i.e., the selection of one item should not be dependent on selection of other item.