Survey & Sampling Methods

Survey

A practical alternative to a census: A survey is designed for the entire population and is recorded by a written response.

Poll

A verbal response

Sampling Frame

Criteria you used to collect your sample. EX: 1,866 registered voters. Registered voters is your sampling frame.

Sample

Must have a numerical value

Entire Population

your study (what you’re interested in).

1. Convenience Sampling

(most basic method) EX: looking around & making a theory of the entire population. Like when you take an exam and look around the students to your left and right to determine how you think the entire class did.

2. Quota Sampling

(the most relevant method, systematic, tedious and scientific). It HAS to correspond to the population (proportional)

3. Random Sampling

any number has an equal chance of being selected from a single set of numbers (more reliable than convenience).

4. Stratified Sampling

Percentages are proportional to your numbers. To find percentage: Divide the small number by the big number x 100%. EX: 400 people divided into 20 people (20/400) x 100% = 5%. Now all percentages must be 5%. If it’s not, it’s quota.

Sampling Proportion

FORMULA: sample/population x 100%. the percentage of the sample relative to the entire population.

Sampling Error

FORMULA: Actual - Sample. EX: 45(actual) - 42(sample) = -3 below (underestimated)

Sampling Statistic

individual. EX: 306 people voted for Smith out of 680 people. 45% voted Smith.