Statistics Ch 1.3

Front 1

Census

Back 1

Collecting data from the entire population rather than taking a space

Front 2

Systematic Random Sampling

Back 2

A method of choosing your sample so that the sampled items are equally spaced throughout the population.

Front 3

Process

Back 3

1. divide the population size by the sample size and round down to m

2. randomly pick a number, k, between 1 and m

Front 4

process cont.

Back 4

3. select the members numbered k, t+m, k+2m

Front 5

Representative Sample

Back 5

one that contains the relevant characteristics of the population in the same proportion (or percentage) as they exist in the population

Front 6

Advantage

Back 6

by spacing out member so of the sample, you are less likely to get a biased sample.

Front 7

Cluster Sampling

Back 7

A method that chooses several items that are somehow already naturally grouped together

Front 8

Example of cluster sampling

Back 8

In chabot's student survey the clusters were classes. Also, the Chabot study was systematic because the courses were equally chosen in the schedule of classes.

Front 9

Disadvantage of Cluster Sampling

Back 9

Clusters usually have like members, thus increasing the chance of getting a biased sample

Front 10

Stratified Sampling

Back 10

A procedure that chooses items from different sleeping sub populations so that they make up the same proportion of the sample as they did in the population.

Front 11

Process

Back 11

1. identify the sub populations they you want to represent.

2. From each sub population, obtain a simple random sample size proportional to the size of the sub population

Front 12

process cont.

Back 12

3. use all members obtained in step 2 as the sample

Front 13

Volunteer Sampling

Back 13

allow participants to volunteer
not randomly chosen
very common and referred to as non scientific studies

Front 14

Convenience Sampling

Back 14

collecting data that is easy to obtain
may survey people you know or attend school with
no attempt at giving equal opportunity to every member of the population

Front 15

Pre existing data

Back 15

occurs any time you collect and examine a data set before you decide what you are going to try to prove from that data

Front 16

Loaded Questions

Back 16

a survey question that has been worded in such a way that favors one answer over others

Front 17

Suspicious Sources

Back 17

when those conducting the experiment or financing the study have a vested interest in a certain result