W4: Idependent Samples t-Test

Question 1

Benefit of adding dependent variables to an experiment

Answer 1

A single IV can be the cause for multiple effects
Converging varints = incease strength that there is an affect present

Question 2

what can you determine from a one-tailed t-test?

Answer 2

where there is a size difference between the groups

Question 3

what can you determine from a two-tailed t-test?

Answer 3

whether the two groups are equal or not

Question 4

student t-test assumptions

Answer 4

• independnece
• homogenatity of varience (equal varience = small spread)
• normality

Question 5

Sientific Integrity

Answer 5

values and beliefs on how scientist treat each other, data, and the public

Question 6

Education Act (1989)

Answer 6

NZ unis must act as the critic and conscience of society:
Freedom of:
* testing and questioning wihtin the law
* engage in research
* regulate content being taught
* how best to teach
* staffing

Question 7

Research Ethics and Te Tiriti

Answer 7

Partnership
Protection
Participantaion
Practice

Question 8

Protection of Human Participants

Answer 8

Rerspect for persons - autonomy
Beneficence - risks + harms = benefit
Justice - burdens and benefit is equal and fair

Question 9

Animal Etics Committee

Answer 9

Reduce - only use as many animals as nessasry
Refine - reduce pain and harm
Replace - dont use animals if possible

Question 10

Type 1 error

Answer 10

False positive/alarm = rejecting H0 when its true and theres no effect

Question 11

Type 2 error

Answer 11

False negative/ miss = failing to reject H0 when its false and there is an effect

Question 12

test statistic

Answer 12

measures the variability tht is caused by manipulation (the effect), compared to the vaiability that occurs natuarely in the population

Question 13

Independent t-test

Answer 13

between-subject
1 categorical IV, 2Levels
Continuous DV

Question 14

t = independent samples

Answer 14

a group differnence / Standard Error of the Mean

when SE produces big t

when t is big or bigger when H0 is true

t is walys a bit bigger than 0 because of SE

Question 15

sampling error

Answer 15

the variability of the observed diffence compared with the true diffrence

how the DV differ between samples due to extranious variables

Question 16

sampling distribution

Answer 16

how often i should expect to observe diff t-stats values by randomly sampling from a single pop.

impacted by df = participants

tells us how often to exect a particular t-value is H0 is true

Question 17

a big t stat =

Answer 17

unlikely to be from the same pop

Question 18

two-tailed t-test

Answer 18

when looking for a diffrence that is non-directional

Question 19

one-tailed t-test

Answer 19

when looking for a difference that is directional

Question 20

two-tailed t-test and H0

Answer 20

we reject H0 if the t is far enough from 0 either way +/-

p-value will be double = more conservative

Question 21

one-tailed t-test and H0

Answer 21

we rejcet H0 if the t is a big enough posive/ negtaive number

Question 22

Assumptions of the Independent Student’s t-test

Answer 22

idependence
homogeneity of varince
normalicey

Question 23

homogeneity is violated - Levene’s test is significant

Answer 23

Welch’s t must be significant to reject H0

Question 24

normality is violated - shapiro-wilk’s test is significant

Answer 24

Mann-Whitney U-test

more powerful test (conservative) so the chnace of Type 2 is reduce

Question 25

definiton of SD of Sample Sample Varience

Answer 25

* how measures differ from the sample mean * spread of your sample

Question 26

Standard Error of Mean (SEM)

Answer 26

how close the sample mean is to the population mean

Question 27

p-value tells us

Answer 27

1. how likely we obtained the result we see if the H0 is true 2. how likely the sample have been draw from the same pop 3. liklihood of a Type 1 error