Research Methods - Data analysis, interpretation and reporting Flashcards
All AS and A2 research methods on the AQA psychology specification are covered as part of this deck
Significance level most often used in Psychology
P<0.05
Determination that the results are significantly strong to reject the null hypothesis
Significance
The likelihood that certain events will occur
Probability
The value a test statistic must reach in order to consider the result significant
Critical value
The value of a statistic that is calculated for a particular data set (outcome of the stats test)
Calculated value
(False-positive) occurs if an investigator falsely rejects a null hypothesis that is actually true in the population
Type I error
(False-negative) occurs if an investigator fails to reject a null hypothesis that is actually false in the population
Type II error
Decreasing the probability of a type I error increases…
the probability of a type II error
How to decrease the likelihood of a Type I error
Use a smaller significance level (P<0.01)
How to decrease the likelihood of a Type II error
Increase the sample size in the study
Choose the test: Difference, nominal data, Independent Measures
Chi Squared (x2)
Choose the test: Difference, at least ordinal data, independent measures
Mann Whitney U (U)
Choose the test: difference, interval/ratio data that is normally distributed, Independent measures design
Unrelated t-test (R)
Choose the test: difference, nominal data, repeated measures
Sign test (S)
Choose the test: difference, at least ordinal data, repeated measures design
Wilcoxon t test (T)
Choose the test: difference, internal/ration data that is normally distributed, repeated measures deign
Related t-test (R)
Choose the test: Correlation, nominal data
Chi Squared (x2)
Choose the test: correlation, at least ordinal data
Spearman’s Rho (Rs)
Choose the test: Correlation, interval/ratio data that is normally distributed
Pearson’s product moment
Sign test: should the calculated value be greater than or less than for significance?
Equal to or less than
Mann Whitney U: should the calculated value be greater than or less than for significance?
Equal to or less than
Wilcoxon: should the calculated value be greater than or less than for significance?
Equal to or less than
Chi Squared: should the calculated value be greater than or less than for significance?
Equal to or greater than
Unrelated t test: should the calculated value be greater than or less than for significance?
Equal to or greater than
Related t test: should the calculated value be greater than or less than for significance?
Equal to or greater than
Spearman’s Rho: should the calculated value be greater than or less than for significance?
Equal to or greater than
Pearson’s Product moment: should the calculated value be greater than or less than for significance?
Equal to or greater than
Which inferential statistic do I have to calculate by hand?
Sign test
Examples of descriptive statistics
Central tendency, measures of dispersion, charts and graphs
Measures of central tendency show what
The average of a set of data (mean, median or mode)
The mean is..
found by adding all scores and dividing by the number of scores - the arithmetic average
The median is..
The central/middle value (once all data is in order)
The mode is…
The most frequently occurring value
Strength of the mean
Most representative as it uses all the data scores
Weakness of the mean
Easily distorted by outliers
Strength of the median
Unaffected by extreme scores/outliers
Weakness of the median
Less sensitive (ignores extreme values that may be important!)
Strength of the mode
easy to calculate
Weakness of the mode
Crude, not very useful, doesn’t represent all the data, might me more than one!
Measures of dispersion show..
The spread of data (range or standard deviation)
The range is
overall data spread. Biggest value minus the smallest value
Strength of the range
Easy to calcuate
Weakness of the range
Doesn’t take into account all data, extreme values only
The standard deviation is
a measure of the average deviation from the mean
How do you calculate standard deviation?
Step 1: Find the mean.
Step 2: For each data point, find the square of its distance to the mean.
Step 3: Sum the values from Step 2.
Step 4: Divide by the number of data points.
Step 5: Take the square root.
What type of graph should I use to represent the strength and direction of a correlation?
Scatter graph/Scattergram
When plotting a scatter gram which co-variable goes on the X axis?
It doesn’t matter!
What type of graph represents the frequency of each variable by the height of its spaced columns and is only used with Discrete data?
Bar Chart
When plotting a bar chart which variable goes on the X axis?
The categories (the IV)
What type of graph displays continuous data and uses the height and width of touching bars to show frequency?
Histogram
The X axis of a histogram must start at..
True 0
What does the Y axis of a histogram represent?
the frequency
A summary table would display…
Raw data
A normal distribution graph looks like…
a Bell curve, symetrical
In a normal distribution the mean, median and mode are
The same (at the highest peak of the curve)
In a normal distribution the tails of the curve never touch what?
The X axis (they are never 0)
A distribution curve that is not symmetrical is known as..
a Skewed distribution
In a positively skewed distribution the curve leans..
towards the Y axis
In a positively skewed distribution, the longer tail is on the left or right?
The right
In a negatively skewed distribution the curve leans..
away from the Y axis
In a negatively skewed distribution, the longer tail is on the left or right?
left
In a skewed distribution curve, the measures of central tendency appear in what order (starting at the top of the curve working down the tail)?
Mode, median, mean
In a normal distribution curve - what percentage of people appear within 1 standard deviation of the mean (either side)?
68%
In a normal distribution curve - what percentage of people appear within 2 standard deviations of the mean (either side)?
95%
In a normal distribution curve - what percentage of people appear within 3 standard deviations of the mean (either side)?
99.7%
DV Data which is in rank order (ranked or rated)
Ordinal data
DV data which is categorical
Nominal data
DV data which is measured in fixed units with equal distance between points on the scale or set intervals
Interval data
Which variable determined the level of data in a study?
Dependent variable
Name the term: refers to the view that gathering data and evidence from experience (sensory information) is central to the scientific method, rather than simply relying upon our
own viewpoints.
empiricism
Name the section of a report: A brief summary (150 – 200 words) of the key points of the study that appears at the start of the report
Abstract
Name the section of a report: Background to the research area and rationale (why the study was conducted).
The background will include a literature review of relevant past studies and
theories,
Introduction
Name the section of a report: Describes how the study was carried out in sufficient detail for someone else to be able to
replicate it.
Method
Name the section of a report: Summarises the findings of the research clearly and accurately. There is normally a section on
descriptive statistics and also inferential statistics.
Results
Name the section of a report: This section explains what the results mean and is broken down into several sections including looking at modifications and implications for further research
Discusson
Name the section of a report: Information on sources of information used in the report shown in alphabetical order.
References
Name the section of a report: Copies of materials that are not suited to any other section of the report
Appendices
What method of referencing is used
Harvard
Outline how an end of test reference should be written
- Author surname then comma and initial followed by full stop
- Publication year in brackets
- Article title with no capitals apart from the first word and full stop at end
- Journal title in italics with a comma
- Volume & issue (in brackets) followed by comma
- Page numbers with hyphen in between and full stop at end
What information goes in an in text reference?
Surname of researchers, year of publication (pages numbers only if its a direct quote)
If there are two or more researcher in the reference how do we link their names?
&
If there are three or more researchers in the reference use
et al.
What are the purposes of referencing?
- To avoid plagiarism.
- Provide a theoretical framework for the topic.
- To acknowledge direct quotes.
- To provide evidence to support arguments.
- So that readers can check how much preparation has gone into your work and can find extra information
When conducted research is assessed by others who specialise in the same field to ensure high quality this is known as
Peer Review
When does peer review happen?
Before research can become part of a journal
What are the aims of peer review?
- Allocate funding decisions
- Validate quality and relevance of research (looking for fraud also)
- Suggest amendments and improvements
Anonymity in peer review can be a problem, why?
Using this to criticise rival research
Publication bias in peer review can be a problem, why?
Tendency to only want significant findings, ground-breaking research otherwise we see the file drawer phenomenon
Why might someone bury groundbreaking research in the process of peer review
It challenges the status quo
We must consider the impact of psychological research on what factor that represents financial sustainability?
The economy
