### Presenting a Sample Using M&Ms

```Step Into the Role of
Researcher Without
Leaving the Classroom
or Clinic
October 27, 2014
Rondalyn Whitney, PhD, OTR/L, FAOTA
Clarkson University OT Department
Acknowledgment for contributions from Sheila Braun and inspiration from Jason M. Molesky
How to think like a
researcher…
What do you want to
know?
Let it Go!
Where do
you get
‘frozen’?
Most of us
get stuck
on the
analysis….
Image from
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We use analysis all the
time in practice….
How to think like a
researcher…
• What do you want to know?
• Who else has investigated
the topic?
• How will you measure it?
• How will you analyze what
you measure?
• What does it all mean?
question
2. Conduct a literature review
3. Establish the methodology
4. Determine the appropriate
statistical measure for your
question and run the
analysis
5. Write the discussion – an
interpretation of what you
learned and how that
compares to the existing
literature.
Basics of Analysis
Method of analysis is predicted by your research
question: Univariate analysis
When you want to know
the number/ count of
data, often shown in the
Mean score…
Nominal data
Frequency
Results will report a count
or a percentage
Example:
Number of boys and girls
in a class.
20 boys, 40 girls
(N = 60; boys n = 20, girls n = 40)
20/60 boys (33%); 40/60 girls
(66%)
Basics of Analysis
Method of analysis is predicted by your research
question: Bivariate analysis
When you want to know if there is
any correlation between two
groups.
The group of females and girl
children have a correlation of 1,
females and boy children have a
correlation of 0. Therefore,
correlation ranges between 0 and 1.
The closer to 1, the higher the
correlation.
Correlation will give you
an r value
Example:
On average scores for difficult
child behaviors are strongly
correlated with maternal stress
(r =.821; p = .001).
Basics of Analysis
Method of analysis is predicted by your research
question: Bivariate analysis
When you want to know if
there is a difference between
two groups.
Did the intervention provided
change the speed of the
child’s performance on written
Did the intervention provided
improve the speed of the
child’s performance on written
A t test measures the
difference between two
groups.
One-tailed measures direction,
two tailed measures change.
Example1:
Using a one-tailed test, the
control group did not show
lower stress than the
experimental group (p=.045).
No relationship was found between high levels of
socially disruptive child behaviors and mother’s
perceived support in the community (p=.798) but both
family support (r =.267, p=.005) and feelings of
cherishment (r =.216, p=.025) showed a weak
correlation.
p value reports the t-test
r value reports the correlation
Most clinical research questions
univariate or bivariate analysis
Basics of Analysis
Method of analysis is predicted by your research
question: Multivariate analysis
Example:
When you want to know
how one variable changes
as a result of the other.
accounts for 17.6% of the total
variance in total stress (F(1, 34)
= 7.252, B = -14.894, p = .011).
Question: What is the
strongest predictor of
maternal stress when raising
a child with disruptive
behaviors?
The greater the number of
words, the lower the total
stress.
Results 3:
Multivariate
account for 22.8% of the
variance in parental distress
(not controlling for anything
else; F(1, 34) = 10.060, B = 6.948, p = .003).
also account for 17.6% of the
total variance in total stress
(F(1, 34) = 7.252, B = -14.894, p
= .011). The greater the number
words, the lower the total stress.
3. A strong and significant
correlation was found between
Difficult Child behaviors and
maternal stress, both before (r
=.810; p= .001) and after the
intervention (r = .891; p=.001).
4. Perceived support predicts
maternal stress and Quality of
Mother-Child Relationship: as
stress increased , support
increased [community (p =. 005),
family (p = .003), and cherishment (p =
.010)]: As dysfunctional
relationship increased, so did
support[community (p = .003),
cherishment (p = .045), Family not a
significant predictor (p = .516)]
5. ASD droped out as a predictor –
cherishment and SPD held in
almost to the end but family
support highest (B = 1.98, p =
.001), difficult child and dysfunctional
mother-child relationship were
covariates.
*bivariate used in regression model
12
Final Model: Average
Total Stress
1.228
Average
ParentChild
Interaction
1.171
1.987
Average
Difficult
Child Score
100% of the
Variance in
Average
Total Stress
Family
Support
Plus a mix of
things we
don’t know
it)
13
All I need to know about
research I learned from a
bag of M&Ms…
What questions can we
ask of a bag of M&Ms
What kind of variable represents
A.Binary?
B. Continuous?
C. Categorical? (a.k.a.
“nominal”)
Huh?
Are the M&Ms binary?
•
You have a binary sample if you have things that can
be in one state or another. Binary means 2, like yes or no
o
Example: M&Ms might be eaten or not eaten.
o
We can call “eaten” a 0 and “not eaten” a 1 (which gives us a value) or leave as
a nominal variable (i.e. a name).
•
You should have a sample that are all “not eaten”
(presumably).
•
This is a CONSTANT. All the values are exactly the same
for all the M&Ms.
Continuous?
• A continuous variable can hold any value
• You have a certain number of M&Ms, so you might say
that “M&M” is a continuous variable.
• You have only 1 bag of M&Ms
• If you had 100 bags of M&Ms of different sizes you might
say the number of M&Ms into your data set for each bag
“One bag of multicolored M&Ms (N = 42)”
• Using a continuous variable, you could come up with
the “mean value” or “average” number of M&Ms found
in each bag
Is the variable “M&M”
categorical?
• You have a categorical variable if you have a
bunch of states (in the case of M&Ms the states
are colors, such as red, yellow, green brown, &
blue).
• Then you can set each CATEGORY to a number
that represents how many you have.
This is the
most useful
unit of analysis
for this study!
Break into small groups
1. separate your M&Ms into colors
2. Create an analysis of your data
3. Report on your findings when we return
as a large group
results
The sample of M&Ms, (N = 57) included a six
colors: orange, brown, green, yellow, blue and red.
Orange and brown appeared with greatest
frequency in the sample (n = 12). The sample
distribution is shown in Table 1.
M&M distribution
(example)
Blue
Orange
Brown
Red
Green
Yellow
8
12
12
6
10
9
Results
question.
• Did you ask how many? Results should give a count
of the total sample
• Did you ask how many of each? Results should give
a count of the sub-variables
two things? Then you should be comparing the
means (averages)
……Etcetera Etcetera Etcetera ….
What’s the best way to tell people
OR
Bar chart?
Pie chart?
Either way. BUT…
• APA 6th recommends using a pie chart to show how a
TOTAL POPULATION is broken down into categories. Here
our total population is the population of M&Ms in your bag
compared with those in the bags of your classmates.
M&Ms per Bag
150
100
50
0
Bag 1
Bag 2
Bag 3
• Use a bar chart when you are showing just a portion of the
population or a series of scalar variables.
So which is better?.
A.Pie chart
B.Bar chart
Table 1: Color distribution in Sample of M&Ms
Yellow
Green
Blue
Red
Orange
Brown
Red
Green
Brown
Yellow
Orange
Blue
0
2
4
6
8
10
12
14
12
10
Blue
8
Orange
Brown
Red
6
Green
Yellow
4
2
0
Blue
Orange
Brown
Red
Green
Yellow
T1: COLOR DISTRIBUTION
(3 GROUPS)
Grand Total
Yellow
Brown
Grand Total
G3
Blue
G2
G1
Green
Red
Orange
0
20
40
60
80
100
120
140
160
Figure 2. Trial 1 bar graph of color distribution for all groups (N = 3)
180
DISTRIBUTION (ALL
GROUPS)
Grand Total
Yellow
Brown
Grand Total
G3
Blue
G2
G1
Green
Red
Orange
0
20
40
60
80
100
120
140
Figure 6. Trial 2 bar graph of color distribution for all groups
160
180
studies?
• Connecting the
dots to
practice….
• Nominal is
nominal is
nominal
• Categorical is
categorical is
categorical…
Verbiage
• Show and report categorical variables or binary
variables using “frequencies” of each category
(“How frequently does it occur?”).
• Show scalar variables using their “mean” and
“standard deviation.”
Verbiage
• “The sample of M&Ms (N = 22) consisted of six colors: red (n =
1), brown (n = 2), green (n = 3), orange (n = 4), yellow (n = 5),
and blue (n = 7).”
• Note the use of past tense. This is correct APA language.
• Note the use of a capital N to represent the entire sample and
the use of lowercase ns to represent the individual groups.
• Note the use of italics to show that you are giving “a statistic,”
or a number that describes your sample.
Another APA Rule
• Never, ever, EVER use
BOTH words AND
pictures to discuss your
sample. Use either
words or an image.
• For instance, to use
only the image, write,
“See Figure 1 for the
breakdown of
frequencies in the
sample.”
• Do not repeat yourself.
• Do not repeat yourself!
Figure 1. Pie chart of
M&Ms.
References
Molesky, J.M. (n.d.) Everything I Ever Needed to Learn
about AP Statistics I Learned From a Bag of m&m’s:
Class Activities for Advanced Placement Statistics
http://web.mac.com/statsmonkey
```