PSY 203 Lecture Notes - Lecture 1: Null Hypothesis, Theoretical Definition, Confounding
24 views2 pages
Lecture 1
Scientific method
- A series of steps to gather knowledge and to be as objective as possible
o No study is perfect
- Steps:
o Identifying a problem
o Form a hypothesis/prediction
▪ A Good Hypothesis can be falsified
▪ Null hypothesis
• No difference in our groups of data
• IV didn’t affect the DV
• Any observed difference is the groups is due to chance/not real/Random variation.
• The groups come from the same parent population
• Null hypothesis testing
o Null hypothesis is what we assume
o Reject or retain the null
o Assume that there are no differences until evidence is gathered
▪ Scientific/alternate hypothesis
• Difference in our groups of data
• IV affects the DV
• Observed differences are Not due to chance (IV, confounding variable)
• Groups come from different population
o Design and experiment/Descriptive research
▪ Think about how to perform the experiment and what you need to do.
o Conduct the experiment
▪ Gather the data
o Testing the hypothesis (using statistics)
o Communication of results (results section)
▪ Data tables and graphs
- Advantages of the Scientific Method
o Trying to gather objective evidence (data); it’s as objective as possible; free from bias.
o Self-correcting
▪ Through replication, if there is something wrong, others can help correct the mistakes.
- Goals of the Scientific Method
o Describe the world around us
o Predict (next stage)
o Explain how something works
o Control, how to fic something
Research Variables
- Variable
o Anything that can change. Ex, Drug usages, depression, mood
- Constant
o Does not change
- Theoretical definition
o Definition of a phenomena in abstract/general terms
o Cannot argue about it
- Operational Definition