analysing data : graphs, sign test Flashcards
(33 cards)
What is a bar chart and when is it used ?
Used when data is divided into categories(discrete data )
a title is needed for a bar chart
the bars aren’t touching
What are scattergraphs and when are they used?
Show association between co variables
shows relationship between variables
What a skewed distribution curve ?
A spread of frequency data that is not symmetrical
it’s where data clusters to one end
What is a negative skew distribution curve ?
Long tail is on the left side and most of the distribution is on the right
the mean is lower than the median and mode
what is a positive skewed disribution curve?
the long tail is on the right side
the mean is higher than the median and mode
What is the symbol that shows equality
=
Which symbol shows much greater than
> >
Which symbol shows much less than
«
Which symbol means proportionate to ?
∝
Which symbol means a a weak approximation ?
approximately equal
≈
What is the level of significance in psychology ?
0.05 / 5%
What are the 5 steps of the sign test ?
1.Work out the sign. Have the values gone up (+) down (-) or stayed the same (=)
2.calculate the “ s” score. This is the lowest score excluding any nil scores
3.calculate the value on N the total number of values the (+) add the (-) excluding any with no difference
4.find the critical s value using the table
5.determine whether results are significant : The value of s must be equal too or Lower than the critical s value
What is the strength of a median ?
Not affected by extreme scores so the average is more realistic of the data set
When should the mode be used ?
Nominal data - data is in categories
What are the 2 measures of dispersion ?
Range
standard deviation
What is a normal distribution curve ?
A symmetrical spread of frequency data that forms a bell shaped pattern.
The mean median mode are located at the highest peak.
what is the symbol for probability?
P
What are the limitations of correlations?
Third variable problem : another unknown variable that is causing the correlation between the other 2 variables “ intervening variable “
doesn’t show cause and effect it only shows the relationship
What is the limitation of a meta analysis ?
Publication bias
where the researcher may not choose to review all information but may leave out thise thaf don’t have significant results
What is the strength of using a mean ?
The most sensitive of all the measures of central tendency as it includes all the scores therefore is is the most representative of a whole data set
What is the limitation of using the mean ?
Easily distorted by extreme values this isn’t good as it stops the mean from being representative of the whole data
What is a strength of using the range ?
Easy to calculate
What is a histogram and when Is it used ?
Used for frequency
The bars touch eachother which shows the data is continuous and not discrete
y axis represents frequency
x Asis is equal sized intervals of a single category
What is a line graph ?
Represents continuous data
uses points and connects it by a line
Shows how something changesin value
iv on x axis
dv on y axis
