T-Tests

Question 1

why do we do experiments? goal of experiments is to determine if the independent variable has a systematic __ on the dependent variable

Answer 1

effect

Question 2

t test family- one sample, two independent samples, __ samples.

Anova family - one - way, factorial

Answer 2

paired

Question 3

is the difference between my groups so large that it is unlikely to be due to chance?.. what helps to answer this question

Answer 3

t test .

Question 4

sampling error: the ___ between the observations in a population and in sample that represents the population in a study

Answer 4

difference

Question 5

null hypothesis: The IV did __ have an effect on the DV m1=m2

Alternate hypothesis: the IV __ have an effect on the DV.
m1/m2

Answer 5

not, did

Question 6

when looking at the difference between groups, we have to judge the ___ between the groups relative to the variability within the groups

Answer 6

difference

calculate range and mean.

Question 7

how do we know if the conditions differ? the key is to calculate the between:

the variability between the group ( difference between means) / (divide)
the variability ___ each of the groups ( variability around the group means)

Answer 7

within

Question 8

the __ extreme the ratio, the more likely it is that group differences were the result of you manipulating and not sampling error

Answer 8

more

Question 9

how do we use a t- value? use it to calculate the __ - value

what does the p-value mean here? the probability, given that the null hypothesis is true m1=m2 that we would expect to get a t-value this ___ or more extreme

Answer 9

p, extreme

Question 10

null hypothesis: m1=m2 
alternative hypothesis: m1does not = m2 
1. if p> .05 
-fail to reject the null hypothesis 
-no good evidence that our -groups differ
we \_\_\_ say that our IV had an effect 

2. if p

Answer 10

cannot, can

Question 11

3 types of alternative hypotheses: non - directional = the means differ m1 does not = differ m2
_____= mean 1 is less/ greater than mean 2 m1m2

Answer 11

directional

Question 12

independent samples t test: requirements: -one IV with __ categorical levels
- the DV is quantitative and normally distributed
- groups must be ___ (ex between subjects)
___ samples t test
- one IV with 2 categorical levels
- the DV is quantitative and normally distributed
- groups must contain the __ participants (ex. within - subjects)
one sample t test - one sample group to be compared with known ___ parameter
-the dv is quantitative and normally distributed

Answer 12

2, independent, same, parameter

Question 13

• t test is a useful tool to test whether group differences are the result of chance (sampling error) or real effects resulting from the IV
• the procedure works by calculating a test statistics based on the __ between group variability to within group variability
• extreme test statistics are good evidence to reject the __ hypothesis.
• t test can be used directional or non directional hypotheses
• t test can be used to compare two independent groups, two paired groups or one group and a known parameter

Answer 13

ratio,