Sample size/Sampling Techniques

n

Positive

sample size is denoted by ____ and is always _____ integer

30

100

Use no less than _____ if possible. ____ or more if you use complex statistics

Estimating the mean/average

Estimating proportion

Slovin’s formula

3 methods in determining sample size

Sampling frame

list of all elements in population, where samples will be drawn

Sampling bias

problem that shows the sample are not represented

Sampling tecniques

plan to ensure that sample will be represented

Probability sample

Non probability sample

two types of sample

Probability sample

it is random, known probability selection, uses sampling techniques

Non probability sample

it is purposive, unknown probability sample, don’t use sampling techniques

Simple random sampling

most basic where there is equal probabilities of selection

Systematic random sapling

obtained by selecting every kth individual of population

Stratified random sampling

separating population into non overlapping groups then obtain a simple random sample from each

Cluster sampling

take sample from naturally occurring groups

Multi-stage sampling

uses two or more steps to select samples

Accidental sampling

Quota sampling

Convenience sampling

Judgement sampling

Purposive sampling

examples of non probability sampling

Non sampling error

Sampling error

2 sources of error in sampling

Non sampling error

error from survey process

Sampling error

errors from using sampling