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Crosswalk Data Analysis Lynn White’s Stats Class Spring 2011. Add the names of all the team members to this first slide . Our Study. State the general purpose of your study. - PowerPoint PPT Presentation
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Crosswalk
Data AnalysisLynn White’s Stats
ClassSpring 2011
Add the names of all the team members to thisfirst slide
Our StudyThe Main Purpose: We wanted to investigate flag
use at a pedestrian crosswalk and the variables that determine whether a flag is used or not.
State the general purpose of your study
ProceduresData was collected…
At the crosswalk across the street from Lins In pairs
One individual on each side of the street The individual on the side opposite the way
individuals crossed administered the surveyOn both weekdays and weekendsDuring daylight hours In clear weather
Give a brief description of the proceduresAnd/or the survey you used
IV’s and DV’s Manipulated or Recorded
Flag/No Flag
Solo/Group CrossingGroup Size
Age
Gender
Resident
Highest Level of Education
Traffic
If children under 18 were present
Our Sample
n= 45Mean Age: 28.23 years old, s = 2.33Men = 21 women = 24
Use descriptive stats to describe yourSample (sample size, # males/females, Mean age and Standard deviation… otherImportant characteristics to define the Sample). Do not report any SEMs here.
What to put on each slide for the statistical testsState the research question you are using statistics to answer be careful with word choice (relationship vs. difference)
When using a t-test or ANOVA: state the IV(s), the levels (separately for each IV - if you have 2 IVs), the DV being analyzed, and the scale of measurement. Make sure you state the FULL name of the test.
When using correlation or chi square, state what the two variables are andtheir level of measurement (hint: for correlation, both need to beInterval or ratio; for chi square, both need to be nominal or ordinal). For chi square, state the FULL name of the test.
Put in a graph (histogram or polygon) with SEMs to show differences between meansPut in a scatterplot to show a correlation ; Put in a table to show chi-square
For each statistical test, you must write out the results in correct APA format. Then state the finding in plain simple English (there are samples in my stats book). Make sure you tell me if the results are significant or not significant.
AESTHETICS COUNT! Make your presentation look DYNAMITE!
Does Age Differ by Residency Status?Independent t-test
IV = residency (CC resident vs. non-CC resident), DV = age (ratio)Not significant t(44) = 1.86, p > .05Mean age did not differ between residents vs.
non-residents of Cedar City
Flag No Flag2727.5
2828.5
2929.5
Mea
n ag
e (y
ears
)
Non-residentresident
Does Flag use Depend on Traffic Congestion?
chi square contingency test: variable 1= flag use (nominal), variable 2 = traffic (ordinal)Not significant χ² (5, N= 45) = 2.20, p > .05. Flag usage does not depend on whether the traffic
was light, moderate or heavy.
Flag usage as a function of traffic
light moderate heavy
No flag 55% 49% 44%
Flag 45% 51% 56%
Note: % are percent of sample within each traffic category
Pearson correlation: variable 1 = years of education (ratio), variable 2 = time to cross the intersection (ratio)Significant, r= .79, p= .000As the number of years in school increased, time
to cross increased.
Is years of education correlated with the time it takes to cross the intersection?
4 6 8 10 12 14 16 18 20 22 240
5
10
15
20
25
30
35
Years of education
Tim
e (s
ec) t
o cr
oss
Does Age Differ by Gender and Flag Use?2 Way independent ANOVA
IV: gender (men vs. women, between subjects) IV: flag usage (no flag vs. flag, between
subjects)DV = age (ratio)Neither main effect was significant at p > .05The interaction was significant F(1, 41)= 5.49,
p=.002
no flag flag05
101520253035 men
mea
n ag
e
The mean age of women wasthe same for flag carriers andnon-carriers.
The mean age of men who carried flags was significantlyhigher than the mean age ofmen who did not carry a flag.
ConclusionsMean age did not differ by residency status
Flag use did not depend on traffic congestion
Years of education was positively correlated withtime to cross the intersection
For women: mean age did not differ betweenCarriers and non-carriers
For mean: flag carriers were significantly olderThan non-carriers