Statistical Design and Analysis
Introduction to Statistics
School of Mathematical and Physical Sciences
Statistics is all about DATA
Describing DATA summarizing, visualizing
SDA 33116- Lecture 1
Data: A set of measurements (variables) taken on a set of individual units (cases) that can
be used to yield conclusions/make comparisons.
Dataset: a way of presenting data comprising of variables measured in cases.
Experiments and Observational Studies
Association (correlation): Two variables are associated if values of one variable tend to be
related to values of the other variable. Association does not imply cause.
Causation: Two variables are causally a
Statistics Lecture 6
Introducing Hypothesis Tests
Statistical Test: Uses data from a sample to assess a claim about a population. Framed with two
Null Hypothesis (H0): Claims that there is no effect or difference
Inference for Slope
1. State Hypothesis
H0: Slope =0 variable x gives no information about variable y
HA: Slope does not equal 0. Knowing x gives some information about y.
2. Calculate Test Statistic
Slope y=a +bx.
Statistical Inference: The process of drawing conclusions about the entire population based on
information in a sample.
Parameter: Number that describes some aspect of a population
Statistic: A number that is computer fr
Statistics: Lecture 3
One Quantitative Variable
1. Dotplot: Each case is represented by a dot and dots are stacked. Identifies outlier cases.
2. Histogram: Quantitative data with numeric x-axis. The height of each bar corresponds to the
Statistics Lecture 10
Chi- Square goodness of fit
Chi Sqaure goodness of fit : Single Categorical Variable
Testing proportion for several categories
H0 : specifies a proportion for each category
HA: At least one proportion is wrong
Observed Counts: actual
Analysis of Variance (ANOVA)
Analysis of variance is used to test for a difference in means between groups by comparing the
variability between groups to the variability within groups.
1. State hypothesis:
Ho = all means are equal 1 = 2 = 3 = 4
Statistics Lecture 9
Determining Statistical Significance
The sample would be extreme if H0 were true
The results are statistically significant
There is evidence for HA
Small p value <0.05
Do not reject H0
The sample would not b
Autumn 2014- Main Exam
l I I I
UNIVERSnY OF TECHNOLOGY, SYDNEY
This paper and all materials issued must be returned at the end of the examination.
They are not to be rernpvetffrom the exam centre.
Two Quantitative Variables
Direction of Association
Positive Association: Values of one variable tend to be higher when values of the other variable
Negative Association: Values of one variable tend to be lower when values of the ot