Class Notes (808,820)
Canada (493,405)
Sociology (749)
SOCI 200 (36)
Lecture 5

Lecture 5 continued (Jan 19th).doc

2 Pages
Unlock Document

University of British Columbia
SOCI 200
Silvia Bartolic

4. External Validity This aspect of validity relates to the degree that research findings (from a sample) can be generalized or extended to (1) the population or (2) similar contexts. Aspects of the sample are critical when evaluating external validity. Recall that aspects of the research design and in particular the research method are critical when evaluating internal validity. We will review THREE sampling approaches that affect external validity. a) Probability Sampling In this approach, you must begin by identifying a population. After you have (1) defined a population, (2) you draw a sample of participants from the population, then (3) conduct your study to reveal findings that pertain to the random sample or participants, and then (4) you generalize the findings you obtained from the random sample back to the population. You can mathematically calculate the probability that your sample is representative of your population. For example, 500 objects or people are defined in your population. You randomly select 100. So the probability that your sample is representative of the population is 20%. The higher the percent; the greater the external validity. This is why sample size affects external validity. b) Random Sampling If you randomly select a sample from a defined population, this increases external validity as well. Random sampling means that each object or individual in the population had an equal chance of being selected as a participant in the study. c) Purposeful Sampling This type of sampling occurs when it is not possible to randomly select participants from the population nor calculate the number of object
More Less

Related notes for SOCI 200

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.