scientific methods

• features of a scientific study:

  -theory construction

  -hypothesis

  -empirical scientific method
• what must an empirical scientific method be?

  -objective(no bias)

  -falsifiability(ability to be proven wrong)

  -replicable(shows reliabilit)
• theory construction is a set of laws to explain a phenomenon
• paradigm is a distinct set of ideals which are commonly accepted. for example- accepted theories, methods of research.
• paradigm shift is when a theory or method is challenged in a way which means that a new way of researching or a new theory becomes accepted in its place
• operationalised means a clear and specific statement
• directional hypothesis predicts the direction of effect you must include all of the independent variables
• non directional hypothesis does not predict the direction of effect
• null hypothesis states that there is no like between the cause and effect
• a sample is a group of people who take part in an investigation
• sampling is the process of selecting a representative group from the population under the study
• opportunity sampling uses the people available at the time who are willing to take part, it is based on convenience
• a strength of opportunity sampling is that is it not time consuming
• a weakness of opportunity sampling is that it may be bias as it doesn’t represent the population
• volunteer sampling is made up of people who self select into the study
• and advantage of volunteer sampling is that it is quick and easy and the participants are willing to take part
• a weakness of volunteer sampling is that it is not representative of the population as it is not random
• random sampling is a method of selecting a sample from a population by selecting individuals from the population at random
• and advantage of random sampling is that there is no bias
• a disadvantage of random sampling is that it is not representative
• systematic sampling is when you divide the number of people in the population by the number you want in the sample which gives you a number (n) you then take every nth number from the population
• an advantage of systematic sampling is that it is representative of the population
• an disadvantage of systematic sampling is that it can be time consuming and sometimes bias
• stratified sampling is when you split the pop into subgroups and select the sample based on the proportions they appear in the population
• an advantage of stratified sampling is that it is representative of the sample
• a disadvantage of stratified sampling is that it is time consuming
• Aim


  A clear, concise statement that specifies what a researcher wants to achieve in their study.
• Aim vs. Hypothesis

  Aim is a broad statement of what to investigate; Hypothesis is a specific, testable prediction about the outcome.
• extraneous variables are variables that can be prevented as they may have an effect on the dependent variable
• confounding variables are unexpected variables that end up causing a change in the dependent variable and independent variable
• participant variables are variables that show difference among participants and can potentially change dependent variable
• demand characteristics are when participants change their behaviour due to them finding out/guessing the aim of the study
• researcher investigator effects is when the investigator leads/clues hints to participants in order to change their behaviour
• situational variables are environmental factors that effect dependent variables. this includes setting, instructions ect
• to control situational variables you need to standardise the study
• Standardize

  To make measurements or operations consistent and uniform across a study or experiment
• to fix impact of participant variables you need to match up individuals with the same variables
• to stop participants guessing the aim you can use deception if declared after as well as single blind design where the participants are unawafe of which conditions they are in
• to control investigator effects you can use randomisation or double blind trials so the conductor is blind to the hypothesis
• independent measures is using different participants for each condition of the experiment