Flashcards in Chapter 4 Designing Studies Deck (25):

1

## population

### the entire group of individuals about which we want information

2

## sample

### a part of the population from which we actually collect information, with this information from the sample, conclusions can be drawn about the entire population

3

## convenience sample

### the result of choosing individuals who are easiest to reach

4

## bias

### shown in the design of a statistical study if it systematically favors certain outcomes

5

## voluntary response sample

### consists of people who choose themselves by responding to a general appeal, this shows bias because people with strong opinions are most likely to respond

6

## simple random sample (SRS)

### consists of n individuals from the population chosen in such a way that every set of n individuals has an equal chance to be the sample actually selected

7

## table of random digits

### a long string of the digits 0,1,2,3,4,5,6,7,8,9 with the properties; each entry in the table is equally likely to be any of the 10 digits 0 through 9, the entries are independent of each other, knowledge of the table gives no information about any other part

8

## stratified random sample

### to select one, first classify the population into groups of similar individuals

9

## strata

### taking a population and classifying it into groups of similar individuals, then choose a separate SRS in each stratum and combine these SRSs to form the full sample

10

## cluster sample

### to create, first divide the population into smaller groups, then choose an SRS of the clusters, all individuals in the chosen clusters are included in the sample

11

## clusters

### should mirror the characteristics of the population

12

## under coverage

### occurs when some groups in the population are left out of the process of choosing the sample

13

## non response

### occurs when an individual chosen for the sample can't be contacted or refuses to participate

14

## observational study

### observes individuals and measures variables of interest but does not attempt to influence the responses

15

## experiment

### deliberately imposes some treatment on individuals to measure their responses

16

## confounding

### occurs when two variables are associated in such a way that their effects on a response variable cannot distinguish from each other

17

## treatment

### a specific condition applied to the individuals in an experiment

18

## experimental units

### the smallest collection of individuals to which treatments are applied

19

## subjects

### individuals, such as humans where the treatment is applied to

20

## random assignment

### in an experiment, meaning that experimental units are assigned to treatments at random, using a type of chance process

21

## completely randomized design

### treatments are assigned to all the experimental units completely by chance

22

## double-blind

### neither the subjects nor those who are interact with them and measure the response variable know which treatment a subject received

23

## statistically significant

### an observed effect so large that it would rarely occur by chance

24

## block

### a group of experimental units that are known before the experiment to be similar in some way that is expected to affect the response to the treatments

25