LECTURE 1 basics

Question 1

null hypothesis

Answer 1

n0

no effect will be found

Question 2

alternative hypothesis

Answer 2

n1
effect will be found

direction - one tailed ie reading will be better
no direction = 2 tailed by less significant or accurate

Question 3

define IV

Answer 3

variable being manipulated

Question 4

define DV

Answer 4

variable being measured

Question 5

define population

Answer 5

whole population refers to the whole group of people aiming to find out about

Question 6

define sample

Answer 6

subset of the population aimed to represent the population as a whole so can generalise results - approximates the population - multiple trials and re sampling provide differing estimates of the population that are used to get a whole idea

Question 7

what is variation that is not produced as a result of iv manipulation between two groups

Answer 7

unsystematic variation (variation due to iv manipulation called systematic variation) - must be controlled for by randomisation of participants and counterbalance of conditions

Question 8

describe measures of central dendency

Answer 8

mode - most frequent score
median - middle score
mean - average by add up and divide by no. scores

Question 9

define categorical variable

Answer 9

nominal - no mathematic meaning ie country or birth, gender etc
mode measure of central tendency

Question 10

define ordinal variable

Answer 10

differenced between scores may not be equal ie 1st and 2nd place - cant use arithematic
use ranks
median central tendency

Question 11

define continuous variable

Answer 11

scale - difference between points are equal 
0 indicates absence = ratio level
0 not indicate absence  = interval 
arithematic possible
mean as measure of central tendency

Question 12

define range

Answer 12

difference between top and bottom score

Question 13

define variance

Answer 13

subtraction of each score from mean, squares added and divided by no. scored -1

Question 14

box plot

Answer 14

summarise data on median and interquartile range containing 50% value

Question 15

STDV

Answer 15

SQRT of variance - standardised measurement

Question 16

STDERROR

Answer 16

STDV / SQRT of sample size

Question 17

confidence interval

Answer 17

95% CI to look at nromal distribution - 95% fall within +/-1.96 SD either side of the mean

Question 18

define the p value

Answer 18

probability that the observed difference between two sample means would have occured if both samples were randomly selected from the same population - probability of finding the observed data if the null hypothesis were true

small - reject null (p

Question 19

define type 1 error

Answer 19

probability that something is declared significant when NOT

Question 20

define type 2 error

Answer 20

probability that failed to reject null even though there is a real effect - two samples actually from different populations