As per the requirements for this unit, we need to be able to explain experimental and non-experimental methods of research
What this means in practice is you will need to identify the research method applied to a certain scenario and talk about the advantages and disadvantages of using that specific method. You will also need to be able to describe alternative methods which could have been applied and again, give the advantages and disadvantages.
This handout is going to be your research methods in psychology bible. EVERYTHING you need to know, and more, is in this handout. If I mention 'the booklet' or 'handout' in any of these pages, this is what I'm referring to!
Click the icon in the corner to open the doc in a new tab then click file -> make a copy to save your own, editable copy.
The simplypsychology page is also pretty good!
We're going to look at both categories as well as the specific types of research which belong to each. If you're taking notes, these might make good page-headers or central nodes in a mind-map.
Understanding research methods and the difference between experimental methods and non-experimental methods is tricky business. The article below gives a really good overview of a bunch of different types of research but for now, focus on the section "What Are The Differences Between Experimental and Non-Experimental Research? " and read the examples.
Understanding the difference between the different types of research is something that comes with lots of practice and time. In general terms, we can distinguish between the two using the following points.... Read them, then read them again.
EXPERIMENTAL METHODS
"The key features of experimental research is that the researcher controls all aspects of the study, especially what participants experience during the study. In particular, the researcher manipulates or varies the predictor variables (IVs), and then allows the outcome variable (DV) to vary naturally. The idea here is to deliberately vary the predictors (IVs) to see if they have any causal effects on the outcomes"
Experimental research is almost always concerned with establishing CAUSE and EFFECT.
NON- EXPERIMENTAL METHODS
"Non-experimental research is a broad term that covers “any study in which the researcher doesn’t have quite as much control as they do in an experiment”. Obviously, control is something that scientists like to have, but as the previous example illustrates, there are lots of situations in which you can’t or shouldn’t try to obtain that control. Since it’s grossly unethical (and almost certainly criminal) to force people to smoke in order to find out if they get cancer, this is a good example of a situation in which you really shouldn’t try to obtain experimental control."
Let's break down some of the key terms from the EXPERIMENTAL METHODS above to make sure we understand what's what...
People sometimes struggle with the concept of 'control' when it comes to research. It's no different to your normal definition of control - no fancy double-meanings here - and simply describes the level of input the experiment has in relation to the variables used / setting of the research / participants used / etc.
A variable in research simply refers to a person, place, thing, or phenomenon that you are trying to measure in some way. In experimental research there is always an INDEPENDENT VARIABLE (IV) (called predictor variable above) and a DEPENDENT VARIABLE.
For Example...
Independent variable (IV) –
This is the variable that the researcher manipulates. If a researcher decides to investigate the effect of caffeine on reaction times the independent variable is amount of caffeine.
Dependent Variable (DV) –
This is the variable that is affected by the manipulation of the IV. So, in the above example, the dependent variable (or what is affected by the amount of caffeine) is reaction times.
For each of the following scenarios, see if you an identify the independent and dependent variables? Where possible, also say what the different 'levels' or 'conditions' of the independent variable could be used. (PS these are on p.9 of the handout too)
If in doubt, a good rule of thumb is to try to rephrase the scenario into "[IV] will affect [DV]"
A researcher wants to find out if people will recall a greater number of short words or long words.
Research is being conducted into whether people over 60 can answer a greater number of general knowledge questions than people under the age of 20
A researcher is interested in finding out if teenage boys have a faster reaction time than teenage girls.
A team of researchers want to know whether people are more likely to buy ‘The Big Issue’ from a seller who has multiple facial piercings and a mohican or from a seller who has no piercings and a short haircut.
A researcher is looking to investigate whether sober or drunk people are better able to recite their times-tables
Along side our experimental variables (the IV and DV), we also have these outside or extraneous variables which are variables that could essentially muck-up your experiment up if you don't take steps to combat them or at least acknowledge their effect.
For example, going back to our example of 'the effects of caffeine on reaction times' we know our independent variable (IV) is amount of caffeine and our dependent variable (DV) is reaction times... what other EXTRANEOUS variables might have impacted reaction times?
Age (Older adults and very young children have slower reaction times)
Hours slept (Maybe some of the participants only had 2 hours of sleep last night while others had plenty?)
Noise (One day, there are roadworks going on outside your 'laboratory'... this could make reaction times longer as it might distract participants?)
What other extraneous variables can you come up with?
Research methods can be split into two main categories; experimental and non-experimental
Experimental research looks to establish cause and effect between an independent variable (IV) and dependent variable (DV)
They do this (and the main difference versus non-experimental methods) by having HIGH control over their research
In research, the independent or predictor variable is the one that researchers change so may have multiple conditions
The dependent variable is the one which is expected to change as a DIRECT result of alterations to the IV.
A laboratory experiment is an experiment conducted under highly controlled conditions (not necessarily a laboratory), where accurate measurements are possible.
The researcher decides where the experiment will take place, at what time, with which participants, in what circumstances and using a standardized procedure.
Participants are randomly allocated to each independent variable group. An example is Milgram’s experiment on obedience or Loftus and Palmer's car crash study.
Field experiments are conducted in the everyday (i.e. real life) environment of the participants. The experimenter still manipulates the independent variable, but in a real-life setting (so cannot really control extraneous variables).
The degree of control that the experimenter has in a field experiment is much less than in that of a laboratory experiment so cause and effect claims are much more difficult to make.
An example is Holfing’s hospital study on obedience.
Psst, this clip isn't research but does meet the criteria for 'observational'... AGNB!
This is a process researchers use when watching, listening and recording behaviours. People are usually observed in their own or a natural environment. This is a non-intrusive method of research, meaning that the researcher does not intrude in any way. This makes it a good method for obtaining data about children, people who do not readily agree to research and animals.
Interviews and questionnaires are similar but also have some key differences. Questionnaires can be completed at a remove while the researcher has to be present for an interview. As well as this, interviewing is a skill so researchers need more training versus questionnaires.
Both of these techniques involve asking a series of questions and recording participants responses.
Questionnaires and interviews can use open or closed question types - closed questions provide people with a fixed set of responses (this or that), whereas open questions allow people to express what they think in their own words (tell me about...).
Psychologists can use experimental or non-experimental methods when conducting research
The method chosen will depend on the goals/aims of the investigation and the practical limitations
All methods have strengths and weaknesses
Experimental methods include laboratory experiments and field experiments
The key difference between experimental and non-experimental methods is that the former has higher controls and can be used to establish cause and effect
Non-Experiment methods include observations and interviews / questionnaires
Complete 'Research Methods Two' on Google Classroom to show your understanding of the different types of research methods.
Remember the handout above has lots of info
References/Resources:
Navarro, D. (2020, July 4). Experimental and Non-experimental Research. Retrieved March 12, 2021, from https://chem.libretexts.org/@go/page/3948