3.2.3.1 Scientific processes Flashcards
What is an aim?
General statement of what the researcher intends to investigate
What should you always start aims with?
Always start with “TO INVESTIGATE”
What is a hypothesis?
Clear, precise, testable statement that states the relationship between the variables being investigated
When should you write a directional hypothesis?
Used when findings of previous research suggests a particular outcome
When should you write a non-directional hypothesis?
Used when there’s no previous research/previous research is contradictory
State the one-tailed formula (directional)
There will be a significant (state change i.e. increase/decrease) in (DV) for (IV 1 - one which change relates to) than (IV 2)
There will be significant increase in spelling scores out of 20 for children that eat 10g of oily fish a day than children that do not eat any oily fish a day
State the two-tailed formula (non-directional)
There will be a significant difference in (DV) between (IV 1) and (IV 2)
There will be significant difference in spelling scores out of 20 between children eat 10g of oily fish a day and children that do not eat any oily fish a day
State the null hypothesis formula
There will be no significant difference in (DV) between (IV 1) and (IV 2)
There will be no significant difference in spelling scores out of 20 for children between eat 10g of oily fish a day and children that do not eat any oily fish a day
What are variables?
Factors that can change within an investigation
Define Independent Variable
Variable that’s changed/manipulated by researcher
Define Dependent Variable
Variable that’s measured by researcher
Define Extraneous Variable
Variable that may have an effect one results of experiment BUT is not the IV
Define Operationalisation
Clearly defining variables in terms of how they can be measured
Define Standard Procedures
Way of ensuring that all participants receive same instructions & completes same tasks to have consistence in experiment
Why can cause and effect can be achieved in lab experiments?
By having one thing different = researchers can conclude that any differences in measured behaviour of participants (DV) is due to one that differs (IV)
Describe Counterbalancing
To control order effects: participants are split in half
- 1 half completes task 2 followed by task 1
- 1 half completes task 1 followed by task 2
What are order effects?
How order when participants do conditions affects the results (better or bored)
Name 2 types of extraneous variables
- Random Errors
- Constant Errors
What are random errors?
Variables that cannot be predicted
Give an example of random error
e.g. participants state of mind/mood, whether they’re ill/cold on the day
Name 2 ways we can deal with random errors
- Eliminate them by standardising = make sure all participants have same experience
- e.g. same room, same questions, same instructions
- Dealt by randomly allocating participants to experiment and control conditions = effects of errors might be balanced out
What are constant errors?
EVs that have more of an effect on one condition of experiment than other
Name an example of constant errors
Participant characteristics (e.g. personality, intelligence, gender, age)
When do constant errors occur?
When psychologists hasn’t randomised or counterbalance correctly
Participants need to by randomised in ways such as… (name 3 ways)
- Random allocation of order of the conditions
- Random allocation of participants to conditions
- Randomly allocate information in conditions
Name 5 sampling techniques
- Random Sample
- Systematic Sample
- Stratified Sampling
- Opportunity Sample
- Volunteer Sample
Define Random Sampling
All members of target population have equal chance of being selected
Random Sampling
Procedure
List of all members of target population is obtained & names on list are assigned a number
Random Sampling
Name a pro
- Avoids researcher bias
- No influence over who’s selected ∴ researcher can’t choose people that may support their hypothesis
Random Sampling
Name 3 cons
- Difficult and time consuming
- Can still end up with biased sample
- Participants may refuse to take part = biased sample & unrepresentative
Define Systematic Sampling
Every nth member of target population is selected
e.g. every 3rd house on street
Systematic Sampling
Procedure
- Achieved by having sampling frame (list of people in target population in alphabetical order)
- Then sampling system is chosen (every 5th person) or produced randomly to reduce bias
Systematic Sampling
Name 2 pros
- Avoids researcher bias
- Fairly representative
Systematic Sampling
Name a con
Participants may refuse to take part = biased sample & unrepresentative
Define Stratified Sampling
Composition of sample represents the proportions of people in certain sub-groups (strata) within target population
Stratified Sampling
Procedure
- Identify different strata that make up population
- Calculate proportions needed for sample to be representative
- Participants that make up each stratum are selected using random sampling
Stratified Sampling
Name 2 pros
- Avoids research bias
- Representative sample for strata = generalisations possible
Stratified Sampling
Name 2 cons
- Identified strata can’t reflect all ways that people are different
- ≠ Complete representation of target population
- Expensive and time-consuming