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