Research methods Flashcards
DATA HANDLING
BOOKLET 2
What are the different measures of central tendency?
-mean
-medium
-mode
What’s the mean?
Adding up all values and dividing it by total amount of data available
strength / limitations of mean
+
representative of all data as it includes all values
-
Distorted by extreme values
Medium?
the middle value in data when arranged in order
strength / limitation of medium?
+
extreme values do not affect it
-
not all values are included (highest + lowest not taken into account)
Mode?
The most frequently occurring value
strength / limitation of mode?
+
easy to identify / calculate
-
crude measurement - may not be representative of all data
sometimes more than 1 mode
Measure of dispersions?
how spread out the data are
-Range
-Standard deviation (SD)
Range?
Minusing the lowest values from the highest
Strength / limitations of range?
+
easy to calculate
- only takes into account extreme values
(the highest + lowest = not fully representative of spread of all scores)
Standard deviation (SD)?
Single value that tells us how far scores are deviated (spread out) from the mean.
the higher the SD = greater the dispersion/ spread out the data is
Strengths / limitations of SD?
+
more precise measure pf dispersion as it includes all values
better than range as it less affected by extreme values
-
takes longer to calculate
Display of quantitative data?
Graphs - way of displaying data to see trends/patterns in data
-table
-bar chart
-scatter gram / scatter graph
-histogram
-line graph
Table?
shows descriptive statistic as well as raw scores
Bar chart
Type of graph which the frequency of each variable is represented by the height of the bars
Scatter graphs
represents the strength + direction of the relationship between co-variables in a correlation analysis
Histogram
Displays the distribution of a whole continuous data set
there is no space between the columns like a bar chart
Line graph
Displays continuous data and uses points connected by lines to show how something changes in value over time
Distributions
types of distributions?
normal distribution
positive skewed distribution
negative skewed distribution
normal distribution
- the mode, median, mean are all equal
- most values near middle
- the graph is symmetrical
Positive skew distribution
- The mean is HIGHER than the median/mode
- long tail is on (positive) right side of peak
-the curve is on the left
Negative skew distribution
- the mean is LOWER than the median/mode
- Long tail is on the (negative) left side of peak
-the curve is on the right
DESIGNING PSYCHOLOGICAL INVESTIGATIONS
BOOKLET ONE
before research is done a aim (purpose) and hypothesis (prediction) is needed:
- Experimental hypothesis?
- Alternative hypothesis?
- Null hypothesis?
- An experimental hypothesis predicts what change(s) will take place in the dependent variable when the independent variable is manipulated.
- The alternative hypothesis states that there is a relationship between the two variables being studied (one variable has an effect on the other).
- The null hypothesis states that there is no relationship between the two variables being studied (one variable does not affect the other).
Experimental and alternative hypothesis can be either directional or non-directional.
- Directional hypothesis?
- Non-directional hypothesis?
- A directional (one-tailed) hypothesis predicts the the effect of the IV on the DV, AND in which direction the change will take place. (i.e. greater, smaller, less, more)
E.g. adults will correctly recall more words than children.
- A non-directional (two-tailed) hypothesis predicts that the IV will have an effect on the DV, BUT the direction of the effect is not specified. It just states that there will be a difference.
E.g. there will be a difference in how many numbers are correctly recalled by children and adults.
what’s a pilot study and its purpose?
A small scale trial of the study before it takes place, where potential problems are identified / target behavior categories are identified before
so they can be fixed before so that the study/observation/interview can occur more smoothly
Types of observations + evaluation:
- Participant observation
observer becomes part of the group they’re studying
+ can experience situation as it is and get valuable insight
-lose objectiveness and get bias by identifying with them too much
- Non-participant
researcher remains separate from those they are studying + record behavior in a more objective manner
+ remains objective
-loses valuable insight into the lives of ppl they’re observing
- covert
the ps are unaware they’re being observed (no consent)
+ removes demand characteristics = higher internal validity
- problems with ethics as they have no consent
- Overt
the ps know they’re being observed
+ more ethical as they give consent
- demand characteristics = low internal validity
- naturalistic / unstructured
takes place in setting / context where the target behavior would normally occur
aspects of environment are free to vary
+ high external validity - can apply to everyday situation
- lack of control over situation and extraneous variables = difficult to replicate and low internal validity
- controlled / structured
watching / recording behavior within a structured environment with variables controlled
+ high control over extraneous variables = easy to replicate and higher internal validity
- more demand characteristics and cant generalize to everyday situations - low external validity
Behaviour categories?
target behaviour is broken down into components that are observable and measured.
the 2 sampling methods for observing behaviour categories?
event sampling: target behaviour is first established and then researcher records this each time it occurs
time sampling: records the behaviour in a fixed time frame
issues with observational designs:
- observer bias
- when the observer is actively looking for certain behaviour so more likely to ‘see’ the, + record them
- only notice events that confirm their opinions / hypothesis
how can it be corrected?
Inter observer reliability:
- carried out by 2 researchers at least
- record separately
- compare observations they got after
- find correlation
=reduces bias and pick up on more detail
issues with behaviour categories
- must be observable + measurable + self-evident
- categories must be exclusive and not overlap
- ensure all possible forms of that behaviour included
observational design AO3
- event sampling useful for behaviour thats infrequent and easy to miss
- time sampling reduces amount of observations needed
- might be unrepresentative of the entire time as they only measuring behaviour in a specific time period