SCS 2150 Lecture Notes - Lecture 16: Sampling Error

• School: University of Ottawa
• Department: Social Sciences
• Course: SCS 2150
• Professor: Ivan Katchanovski

Document Summary

Purposive sample: non-random selection of participants/respondents based on a speci c purpose of a project. Sample of facebook users: only selecting people who use facebook. Quota sample: set quotas for speci c groups. Non-probability/non-random samples are di cult to generalize to population: generally not representative of the population. Sampling error: errors of estimation that occur as a result of di erences between the characteristics of the sample and those of the population. Non-response: occurs if people selected for the sample do not supply the required data. It is the absolute size of the sample that matters, not the proportion of the population that it comprises. As sample size increases, sampling error tends to decrease. Typical sample sizes in national surveys: 1000, 1600, and 2500, generally, the greater the heterogeneity of the population on the characteristics of interest, the larger the sample size should be. Sample sizes can be smaller in other surveys or sample types.