The Basics of Science and Experiments in Psychology Flashcards
Falsifiability
Any hypothesis needs to be testable to prove if its false
Why is psychoanalitics not a scientific theory of psychology
Psychoanalysts source all mental issues to childhood trauma, if the person does not remember their trauma, they say it’s repressed
- this is not falsifiable
Deductive reasoning
An argument which the conclusion necessarily follows
- It is impossible for the conclusion to be false given the premises are true
- Used in mathematics
Inductive Reasoning
You can never be 100% sure of the conclusion
Ex. “all swans that have observed have been white”
DOES NOT = all swans are white
Can you prove a positive?
No
Fact
observation of the world around us
Hypothesis
Questions about an observation
Theory
A well-supported explanation based on lots of evidence
Law (science)
A detailed description of how something happens, usually supported by math
Dependant Variable
The thing that is effected or caused to occur
- the phenomenon we’re interested in
Independent variable
The variable that is expected to cause the behaviour
Operational definition
A description of a variable in themes of the operations used to establish or measure that variable
- Precise
- Practical
- Quantitative
- Good interobserver reliability
Histogram
A graphical representation of ranges of a variable, like a bar graph, but shows a continuity
We like this in psychology
Gaussian distribution (both normal and uniform)
the graph looks relatively the same on the left and right of the graph
Central Tendency
The most typical value of a data set
- Commonly called the average
Mode (statistics)
The value that occurs with the greatest frequency
Ex, 3,4,2,5,4,7,4,3
Mode = 4
What are the pros of using the mode? (Statistics)
- Works well with nominal frequency data (not numbers) ex. Dominant handedness of people
- Can produce sensible values
What are the cons of using the mode? (Statistics)
- Dependent on how you “bin” data
- Low sampling stability (fluctuates a lot from sample to sample)
- May not exist for certain data sets (Could have multiple modes or none at all)
Median
The middle number in an ordered set of data
- If it’s an odd number, find the middle two and take the mean of them
What is the pro of using the median
Robust to extreme values
Mean (statistics)
Add all the values together and divide by how many values there are
Advantages of using the mean? (Statistics)
Best sampling stability
Works with many statistical methods
Cons of using the mean? (Statistics)
- Value may not exist in the real world
- Assumes data is on, at least, an interval measurement scale
- Heavily affected by extreme values
Is an average an accurate representation of the group?
No, you need to look at the whole data set
How do you find standard deviation?
Calculate the deviations
Square them
Take the mean
Remove the square
Standard deviation = ((the sum of( x - mu )^2/N)^(1/2)
Skewness (statistics)
If the graph is skewed more to the left or right
Means and standard deviations are only useful for Normally distributed data
Which “average” should you use if your dataset is skewed?
The median