Summary Part B Statistics 1 (Applying Statistics in Behavioural Research)
35 views 1 purchase
Course
Statistics 1 (SOWPSB1RS10N)
Institution
Radboud Universiteit Nijmegen (RU)
Book
Applying statistics in behavioural research
This document contains the summary of part B of the statistics 1 course of B1 psychology. It was written in 2023 and based on the book Applying Statistics in Behavioural Research by Jules L. Ellis.
Summary Part C Statistics 1 (Applying Statistics in Behavioural Research)
Summary Part A Statistics 1 (Applying Statistics in Behavioural Research)
Summary Statistics 2 Part B
All for this textbook (4)
Written for
Radboud Universiteit Nijmegen (RU)
Psychologie
Statistics 1 (SOWPSB1RS10N)
All documents for this subject (2)
Seller
Follow
isawilms
Reviews received
Content preview
Statistics 1 Summary Part B
(applying statistics in behavioural research)
Basic report of association between two quantitative variables:
- Design, degree of control, and name of the analysis
- Scatter plot with regression line
- Regression coefficients (slope and intercept) and correlation
- List of influential observations
- Indication of linearity
Design
The design specifies the variables that you report about and their (hypothetical causal) role.
Independent variable (x) = the variable that is supposed to be the cause
Dependent variable (y) = the variable that is supposed to be the consequence
The design contains (for both variables):
- the role of the variable (independent or dependent)
- the name of the variable
- the measurement level of the variable (qualitative or quantitative)
- the possible outcomes or levels of the variable
Example:
Dependent variable = grade after studying summary (quantitative, 1-10)
Independent variable = grade before studying summary (quantitative, 1-10)
Degree of control
For the independent variable, state whether it is experimental or not. It is experimental if it is
actively manipulated and randomised.
Name of the analysis
The analysis that is done in this basic report is a simple linear regression analysis. It is called simple
because there is only one independent variable.
Scatterplot
In a scatterplot, each subject is represented by a dot. The score of the independent variable is used
as the horizontal coordinate (x) of this dot. The score on the dependent variable is used as the
vertical coordinate (y) of a dot.
Regression coefficients and correlation
The (linear) regression line is a straight line through the dots in the scatterplot. The line can be
described by the equation:
Y = a + bX
Where:
a and b are regression coefficients
a is the intercept, which is the height at X = 0
b is the slope, which tells you how much the line increases if X increases by 1 unit (1 to the left, ?
upwards)
, The correlation (r) indicates the direction and the strength of the association between the variables.
The correlation is a number between -1 and 1.
You can compute the regression coefficients with the statistical functions of a calculator during the
exam.
Regression line
Now that you have a and b, you can use Xmin and Xmax to calculate the coordinates of the two ends
of the regression line.
Example:
a = 2.75
b = 0.55
so then the formula is
Y = 2.75 + 0.55X
Then you fill in the formula with Xmin (3) and Xmax (7)
Y = 2.75 + 0.55*3 = 4.4
Y = 2.75 + 0.55*7 = 6.6
So, the coordinates that you use to draw the regression line are
(3, 4.4) and (7, 6.6)
Find the coordinates in the graph and draw a line between them.
Influential observations = observations that have a large impact on the correlation
When in doubt whether a certain point is influential, compute r 2 with, and without that point. If the
difference is larger than .20, the point is influential.
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 or Stuvia-credit 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 isawilms. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.25. You're not tied to anything after your purchase.
