Research

Question 1

Systematic error

Answer 1

deals with accuracy ( decreases accruacy)

Question 2

random error

Answer 2

Random and could not be induced by a particular experimental modification. example: system malfunction.

decreases precision

Question 3

precision

Answer 3

how closely individual measurements of the same value agree with each other.

Question 4

accuracy

Answer 4

how true to original value

Question 5

experimental study

Answer 5

scientists manipulate one or more variables in prder to observe the outcome

Question 6

Observational study

Answer 6

• nonexperimental

- do not manipulate but just observe the variables

Question 7

Types of observational study

Answer 7

• cross sectional study
• cohort study
• case-control study

Question 8

Cross sectional study

Answer 8

studies a sample of the population at one point in time

Question 9

cohort study

Answer 9

studies a sample of population over time

Question 10

case-control study

Answer 10

studies two sample populations, one with and one without an outcome.

Question 11

when is a t test used?

Answer 11

most appropriate to compare means for each of the variables.

• compare teh means of two groups when the dependent variable is continuous.

Question 12

when is a chi test used

Answer 12

used when variables are categorical

Question 13

when is a chi test used

Answer 13

used when variables are categorical

Question 14

Paired t test - commonly used in before and after studies

Answer 14

• compares the distributoin of two groups when each value within a group has a natural partner in the other group.

Question 15

statistical signficance = null hypothesis is rejected

Answer 15

the difference between two different groups is signficant.

example if p=0.04, 4 % probability of any difference between group occurs by chance, and reject the null hypothesis.

Question 16

statistical signficance = null hypothesis is rejected

Answer 16

the difference between two different groups is signficant.

example if p=0.04, 4 % probability of any difference between group occurs by chance, and reject the null hypothesis.

Question 17

what does it mean when the p value is 0.01?

Answer 17

there is one percent chance that the null hypothesis is correct. reject the null hypothesis. The difference between groups could be due to random chance.

Question 18

what does it mean when the p value is 0.01?

Answer 18

there is one percent chance that the null hypothesis is correct. reject the null hypothesis. The difference between groups could be due to random chance.

Question 19

define confounding variable

Answer 19

a variable that is correlated with independent variable and has a casual effect on the dependent variable.

Question 20

internal validity

Answer 20

refers to whether a casual relationship between the independent and dependent variable can be justifiably concluded from an experiment.

• it can be greatly affected by confounding variables

Question 21

External validity

Answer 21

refers to the generalizability of results from a sample to a wider population, and is determined by factors like whether or not the characteristics of sample are representative of those of the population.

Question 22

Consent must be OBTAINED prior to the commencement of a study if there is a potential for emotional/physical harm for the participant in the study.

Answer 22

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Question 23

Consent must be OBTAINED prior to the commencement of a study if there is a potential for emotional/physical harm for the participant in the study.

Answer 23

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Question 24

When an experimental design of a study does not actually test the situation it purpots - what happens?

Answer 24

it lacks construct validity

Question 25

Scientic method

Answer 25

• asks question
• do background research
• construct hypothesis
• test hypothesis via experiment
• analyze data/draw conclusion
• communicate results

Question 26

Criterion Validity

Answer 26

refers to whether a variable is able to predict a certain outcome

Question 27

mediating variable -

Answer 27

one that explains relationship between 2 other variables

Question 28

moderator variable

Answer 28

one that influences the strength of a relationship between 2 other variables

Question 29

confounding variables

Answer 29

• one which is an extraneous variable that is related to both dependent and independent variable.