Maths And Psychology

Question 1

Bar chart

Answer 1

To compare sets of quantitative data
must be different groups or sets the bars cannot touch on another unless two bits of quantitative data with the same group/set

Question 2

Histogram

Answer 2

Frequency of a set piece of data
EG lists of quantitative data that is similar

In a histogram all lines must touch and the y axis must be frequency

Question 3

Scatter graph

Answer 3

The results of two sets of quantitative data represented as a point from each value of the x axis and y axis where they intercept

Dots must be right for both the axis to plot them

Question 4

Pie chart

Answer 4

Percentages of data out of 100% represented in a circle using angles all percentages of data must add up to 100%

Question 5

Line graph

Answer 5

Two sets of quantitative data in a line connected from dots along the two axis

Dots must be connected and the line must connect to the origin aka 0,0

Question 6

Measures of Central tendency

Answer 6

Mean: all the values added together and then divided by the number of values

Median: the middle value as the scores are in arithmetic order if the middle number is two numbers then do the mean of the two numbers

Mode: commonly occurring value
If there are multiple modes list them in arithmetic order

Question 7

Measures of dispersion

Answer 7

Range: the highest value take away the smallest value

Question 8

Measures of dispersion (standard deviation)

Answer 8

Standard deviation = the square root of the sum of each value minus the range of each value squared over the number of values minus 1

SD=√∑(x-Mean of x)²/n-1

Question 9

Levels of significance

Answer 9

We need to at least the 95% accurate which means the probability the results are due to chance (p) must be 5% or (p=0.05)

Question 10

Statistical tests

Answer 10

When testing correlation use a spearman’s rho

When testing nominal independent measures data use a chi-square

When testing ordinal independent measures use a Mann Whitney U

When testing an ordinal repeated measures use a wilcoxon T

Question 11

Types of data

Answer 11

Nominal data (catagorys)

is when you can count the number of participants who did one thing or another will fall into a category
EG males and females into the categories of comedy films and horror films if they’ve watched them

Ordinal

Results of data given the form of ordinal sometimes called ranked data your told who came first second etc
(data in order)

Interval/ ratio data

data that is more than just order
shows differnces between 1st and 2nd
and 2nd and 3rd and so on
+ if data is exact and in a unit such as seconds, feet, words remembered ect. its interval/ ratio data

Question 12

Frequency table

Answer 12

Three columns first column is what is being The Range in ascending order
if too many values or too high range, a particular interval of data value is chosen

The second column is a tally based on it’s corresponding data

Column is the frequency which is just the number of tally marks

Question 13

Frequency tables and histograms

Answer 13

The data is put as a range on the x-axis and the frequency is on the y-axis

A symmetric histogram is if you could the histogram down the middle the right and the left hand signs are mirror images of each other

Skewed right histogram is when the majority of the frequency of data is to the left and there is few data on the right

Skewed left is when there is a lot more frequency of data on the right and lot less on the left

Question 14

Normal distribution curb on the frequency distribution graph

Answer 14

The mean medium Mode all occur at the same point and have the same value at the highest point in the middle

Is a bell shape and has the same shape either side of the mean the pattern of scores at exactly the same above the mean as it is below

Question 15

Standard deviation and the normal distribution of frequency distribution graphs

Answer 15

The proportion of schools falling between the mean and 1 standard deviation above or below the mean is 34%

The proportion between 1 and 2 standard deviations above or below the mean is 13.6%

The proportion of scores 2 standard deviations above or below the mean is 2.4%

So if the mean is 15 and the standard deviation is free that means 68% scored between 12 and 18 within the one standard deviation above the mean and one standard deviation below the mean

Question 16

Skewed distributions on frequency graphs

Answer 16

Positive skew is where most of the scores lied to the left of the x-axis with fewer scores at the right of the x-axis mean>mode

A negative skew is well most of the schools would lie on the right of the x-axis and less of the schools would lie on the left of the x axis mean<median

On skewed distributions the median mode and mean will not be in the same place

Question 17

mean median mode histograms

Answer 17

The mode will be the highest frequency

Half of the total value then add the frequencies from each group and find the group that has the frequency that is half of the total this is the median

The mean is the middle value of each range in the x-axis Times frequency of each interval then add them all together and divided by the overall frequency

This can be used to do figure out the skew of a histogram

Question 18

Ratios

Answer 18

If the class sizes 31 and two students in the class of autism than the ratio of students with autism to students who do not have autism is 2 : 29 and the ratio between students have autism and the class size is 2 : 31

Question 19

Corolations on a scatter graph

Answer 19

/ positive corolation

\ negative corolation
:•: No corolation
n Curvilinear corrolation

Hypothesis for correlations :
≠ sig difference

=sig relationship

Question 20

Wilcoxon T

Answer 20

Difference of the 1st variable and the 2nd

Rank the differences
(not any that =0)

add up ranks for - diff and + diff
the smallest of these totals = T

N= number of scores (ignore if 0 diff)

Compare in provided wilcoxon Signed ranks test table for Critical value at 0.05 lvl of significance

for either if =/< critical value = significant

ordinal (data that is ordered)

Repeated measures

Differences

Question 21

Man Whitney U

Answer 21

Total ranks between the two groups

U[a/b]
Number if ppts in group A x N in group B + Na/b/2 -Total of ranks [a/b]

U = N° in A X N° in B + 〔NA/B 〕/2 - total ranks of [a/b]

U= the smaller number of U[a] and U[b]

ordinal (data in order)
Independant measures
Differences

Question 22

Spearman’ RHO

Answer 22

Difference of The 2 ranks
difference²
total of all d²

Calculater value =

1-6x[total of d²]/
n(number of ppts) x (n²-1)

then compare calculated value to critical value from spearman’s rank at 0.05 lvl of significance

significant= calc value >/= critical value

Ordinal (data in order)
corrilational

Question 23

Chi Square

Answer 23

Observed - expected
(O-E)²
(O-E)²/E
add all (O-E)²/E together =Chi Square

df= (n° rows -1) × (n° collums -1)
[for the cattagorys only]

then compare Chi square value to (lvl of sig at 0.05 at the df value to get the critical value) the critical value
chi square value >/= critical value =significant

difference
nominal (catagory data)
independant measures

Question 24

Standard Deviation thurther explained

Answer 24

SD=√∑(x-Mean of x)²/n-1

x = score
n= number of Ppts

Question 25

Curvulinear correlation

Answer 25

looks like: n an arc that curves rises to the peak then falls

Question 26

type 1 error

false positive

Answer 26

A false positive

This is Where Null hypothesis may be falsely rejected

The research may falsely claim an effect exists

this is likely to happen when a p-value is to lenient such as p<0.5 or p<0.3

( rejects null hypothesis when it was actually true)

Question 27

Type 2 error

false negative

Answer 27

A false negative

this is where a null hypothesis may be falsely accepted

the research may falsely claimed an effect does not exist

this is likely to happen on a p-value is to stringent such as p<0.01

(accept null hypothesis when actually it was false)