Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Statistics > Exam 1 study > Flashcards

Exam 1 study Flashcards

1
Q

what is an observational study

A

observe only - no interaction or control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is an experiment

A

Exert control to better understand the impact of treatments vs response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are treatments

A

what we do to the person in our experiment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are explanatory variables

A

a variable that we think explains or causes changes in the response variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are response variables

A

a variable that measures the outcome or result of a study

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the difference between a population and a sample

A

A population is ALL, a sample is a subset selected for study

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name the 6 main sampling techniques

A 
Random (SRS - Simple random sample)
Cluster
Stratified
Systematic
Convenience
Voluntary Response Survey
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a cluster study

A

1 group from the population (1 class to represent entire school)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a stratified sample

A

Proportional sampling of the population (College students could be represented by undergrad and grad students. Sample should have correct percentage of each)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a systematic sample

A

Every nth person is selected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a convenience sample

A

Interviewer selects people. Mall survey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a voluntary response survey

A

Depends on individuals to initiate contact, call in polls, online polls. Not valid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is bias?

A

Repeat the same experiment over and over and get the same WRONG result

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Does sample size effect bias?

A

NO!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do we correct for bias?

A

change sampling method. Must have demographics for population to reduce bias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is sampling error?

A

cannot be controlled (variability). Repeating the same experiment over and over variations are sampling error.

17
Q

How can we decrease variability?

A

Increase sample size

18
Q

How do you computer MOE?

A

1/ Square root of sample size

19
Q

What is a confidence interval

A

Result + or - MOE

20
Q

Can sampling error be eliminated?

A

NO!

21
Q

What is the difference between a parameter and a statistic?

A

Parameter refers to population and statistic refers to sample

22
Q

What is the placebo effect?

A

Positive response independent of treatment?

23
Q

What is the purpose of using a placebo?

A

placebo attempts to reduce bias

24
Q

What is a lurking variable?

A

something not being accounted for in the study

25
Q

What are confounding variables

A

measuring more than we need. Variables are confounding when their effects on a response variable cannot be distinguished from each other. Confounding variables can be either explanatory or lurking variables

26
Q

What 3 components are necessary for ethical human studies

A

Institutional Review Board
Informed Consent
Confidentiality

27
Q

What are explanatory variables

A

Controlling the response (what we are changing)

28
Q

What are response variables

A

The outcome of the experiment - what we are measuring

29
Q

What is reliability

A

measure same person, same way get same result. Results can be both reliable and biased

30
Q

What is rate?

A

change/time - more valid measure than a simple count of occurrences (response/population)

31
Q

What is a block design (and can you draw one)

A

random assignment of subjects to treatments is carried out separately within each block. (eg: group (block) patients based on disease and then randomly assign to different treatments)

32
Q

Does an observational study have a design?

A

NO!

33
Q

What is a randomized comparative experiment (and can you draw one)

A

All subjects are allocated at random among all the treatments. eg: all subjects randomly receive either coke, pepsi or RC cola - response variable is BMI - no blocking

34
Q

What is a matched pair design?

A

matched pair compares two treatments eg: does coke or pepsi taste better or it could be two subjects each getting one treatment.

35
Q

Give 3examples of nonsampling errors

A

nonresponse, response error(inaccurate response), processing errors

36
Q

what is a sampling frame

A

list of the subjects

37
Q

what is statistical significance?

A

an observed effect of a size that would rarely occur by chance.

38
Q

what is qualitative

A

numbers without meaning (index)

39
Q

what is quantitative

A

numbers with meaning

Statistics (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions