Quantitative Research Methods Lecture 2

hypothesis

a statement that indicates what the researcher expects to happen

give an example of a hypothesis

there is a relationship between sleep quality and cognitive performance in first year students

experimental hypothesis

what is expected to happen

null hypothesis

what the researcher is trying to disprove or nullify

give an example of an experimental hypothesis

there is a relationship between sleep quality and cognitive performance in first year psychology students

give an example of a null hypothesis

there is no relationship between sleep quality and cognitive performance in first year psychology students

cross sectional study

data collected at one point in time, i.e. SINGLE instance of data collection

longitudinal study 

data collected over period of time (MULTIPLE instances of data)

drawback longitudinal study

loss of participants over time

give an example of longitudinal study

every 5 years or follow children until age 18

when collecting data, what should you observe

non-participant and participant observation

non-participant observation 

observe without interacting 

participant observation

become part of the group while secretly observing

interviews when collecting data 

research asks questions, listens, analyses response

focus group interviews

interview a group rather than individuals one by one

questionnaires

e.g. likert scale responses

when collecting data how should you conduct experiments

one variable manipulated, another variable measured

descriptive statistics 

• broad overview of results 

• researchers often use graphs and charts in order to visualise observed trends and effects 

what are you looking at in your report findings

finding errors/weak spots and biases

name the different types of biases

interview, participant, analyst and researcher bias

interviewer bias

interviewer may influence participants by asking questions in an aggressive way, incorrectly

participant bias 

participants may be unresponsive, give inconsistent responses, provide false answers, underreport/overreport, misunderstand questions or have difficulty expressing themselves 

analyst bias

analysts may incorrectly code data or choose inappropriate analysis methods

researcher bias

the researcher’s decisions at any point may be influenced by their personal views, or their own beliefs may shape their interpretations of the findings

what is the general structure of a research report

1. abstract

2. introduction

3. methods

4. results

5. discussion

6. references

7. appendices

what happens if null hypothesis is rejected 

the research body is strengthened  

what happens if null hypothesis is accepted

• topic needs to be further explored

• return to literature and propose refinements

what is the difference between correlation (r) and causation

correlation is the relationship between variables and causation is the cause and effect

when r = -1

perfect negative correlation

when r = 1 

perfect positive correlation 

r = 0

no correlation

what are the advantages of correlational studies

• ability to study variables that cannot ethically be manipulated

• ability to investigate relationships and variables in their natural settings

• enable us to observe phenomena in the real world

• ability to make predictions based on our research

• usually more cost effective than experimental studies