Summary
Summary Variables and Designs Hypothesis
- Institution
- The University Of Nottingham (UON)
A document creating a summary of all the lecture notes.
[Show more]
Seller
Follow
Content preview
Variables, designs and hypothesesScientific methods (3)
Experiments:
- Vary some independent variable while holding everything else constant
- Measure changes in some dependent variable.
Changes in DV must have been caused by changes in IV
- Can infer causality from this
Quasi – experiment
- Similar to experiment except IV cannot be manipulated (e.g. age of someone, or a
mental disorder, so instead have to allocate these people within their similar group)
- Potential problems with confounding variables (the people with a mental disorder
may be of different ages and so hard to distinguish which group to put them in)
Correlational design
- No manipulation
- Measure 2 (or more) variables and determine the extent to which they are related to
each other (or co-related)
- Cannot infer causality (do not know what caused what)
Variables
Independent Variable:
- Can have one or more IVs or factors
- Each IV can have 2 or more levels, e.g:
- Test ppts reading speed after a meal, before a meal and 2 hours later
- 1 IV (time of day) with 3 levels (before, after and 2 hours later)
Dependent variable:
- An experiment can have 1 or more dependent variables, i.e. what we actually
measure
- E.g. ‘does having A level maths have any effect on the ability to understand an
undergraduate psychology course?’
- ^^potential DVs: 1st year exam marks, 3rd year project marks, final degree outcome.
DVs have several types or measurement scales:
- Nominal scales (categorical):
Numbers refer to different classes
Classes not necessarily related to each other
- Ordinal scales (ranking):
Numbers indicate a relative position (rank) in a list
Rank is meaningful, items not necessarily at equal intervals
- Interval scales:
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller maryonanna. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £6.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
53022 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now