Transcript Statistics

We have a capacity that is nearly infinite
for reading evidence in the light of our
own interests and passions
Statistics
Outline
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Dos and Don’ts of Statistics
Variables
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Independent
Dependent
Types of statistics
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Descriptive
Relational
Inferential
The Dos and Don’ts of Statistics
 Statistics DO:
 provide unbiased quantitative methods for characterizing and
drawing conclusions from experimental data
 Statistics do NOT:
 aid determination of which research questions are important
to ask
 allow manipulation of data to get the answer you want
 help you judge the importance of statistically significant
findings
Variables
 A variable is a biological trait which can take on different
values for different members of the group under study
 Thus, a variable is not a constant, it is a trait which varies
among the experimental subjects
 Examples include protein amounts, migration distance
on a gel, the amount of chlorophyll in a leaf, etc.
Variables
 Variables are either independent or dependent
 Independent variables
 Cause something to happen
 Actively manipulated by the researcher,
 Observed in situ by the researcher
 Dependent variables
 Caused by the independent variable
 Experimental outcomes which are measured during a study
Descriptive Statistics
 Summarize a group of numerical data
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Mean
Variance
Standard deviation
Standard error of the mean
Range
Relational Statistics
 Determine if two or more sets of data show any type
of connection or dependency on each other
 Correlation
 Regression
Inferential Statistics
 Compare two or more groups of numerical data to
determine if they are similar or different
 Compare the treatment and control groups
Activity
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Pair up
Answer the questions on the next page
You have 10 minutes to do this
I will select some of you to share
1.
2.
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4.
5.
What are the
independent variables?
What are the dependent
variables?
What type of statistics
are presented?
What are the results?
What can you conclude
from the results?