What are the steps in a Scientific Investigation?
Dependent variable (DV)
variable affected by manipulation
Independent variable (IV)
variable manipulated
Experiment
manipulation of one variable under controlled conditions so that resulting changes in another variable can be observed (Ex: Coke and Mentos)
What is the theory construction?
Confidence in theory increases
^
Theory > Hypothesis > Empirical Research
v
Revise/refine the theory < Confidence in theory decreases
v
Discard the theory
Operational definitions
are used to clarify precisely what is meant by each variable (e.g., self esteem defined as score on survey)
Participants or subjects
are the organisms whose behaviour is systematically observed in a study
Data collection techniques
allow for empirical observation and measurement
Methods used when a researcher cannot manipulate the variables under study?
Measures of central tendency is?
typical or average score in a distribution
Mean?
arithmetic average of scores
Mode?
most frequently occurring score
Medium?
score falling in the exact centre
Meta-Analysis
Control group
similar subjects who do not receive the special treatment
Experimental group
subjects who receive some special treatment in regard to the independent variable
Statistical significance
when the probability that the observed findings are due to chance is very low
Standard Deviation
numerical depiction of variability
High variability in data set = high standard deviation
Low variability in data set = low standard deviation
Variability
how much scores vary from each other and from the mean
Range = the simplest measure of variability, and the most intuitive
Statistics
using mathematics to organize, summarize, and interpret numerical data
Inferential statistics
interpreting data and drawing conclusions
Descriptive statistics
organizing and summarizing data
Experimental Research disadvantages
- Ethical and practical issues
Experimental Research Advantages
-Conclusions about cause-and-effect can be drawn