as week 7 observation and levels of measurement
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AS Week 7 Observation and Levels of Measurement.TRANSCRIPT
Add more detail to the mind map
Lesson ObjectivesBy the end of the lesson you …
• Must be able to describe (AO1) the observational method and its components.
• Must be able to evaluate (AO2) the observational method.
• Should be able to identify different data types (nominal, ordinal and interval/ratio).
Pg 6-8
Validity and Reliability
Validity refers to the degree to which a study accurately reflects or assesses the specific concept that the researcher is attempting to measure.
Reliability is the extent to which an experiment, test, or any measuring procedure yields the same result on repeated trials.
Validity Reliability
Check Conduct an survey
Inter-rater reliability
(more than one observer)
ImproveCovert
observations(no demand
characteristics)
Agreed coding scheme
(remove ambiguity of categories)
Scenario Based Questions
Select on of the scenarios and answer the questions.
20 mins
If you complete one move onto another or design yourown scenario and answer the questions.
Key Terms - Observation
• Ecological Validity• Non-participant Obs. • Participant Obs.• Undisclosed (covert)• Disclosed (overt)• Structured • Unstructured• Coding Scheme• Controlled Observation
• Event Sampling• Time Sampling• Reliability • Inter-rater Reliability• Validity• Categories• Ethics• Quantitative Data• Qualitative Data• Coding Scheme
Quantitative Data
Qualitative Data
Levels of Measurement
Descriptive vs. Inferential
Descriptive Statistics• Summary of data to illustrate patterns and
relationships – BUT can’t infer conclusions
Inferential Statistics• Statistical tests that allow us to make
conclusions in relation to our hypothesis.
eg. Mann-Whitney or Spearman’s Rho or Chi Square.
DESCRIPTIVE Data Analysis
0.5 1 1.5 2 2.5 3 3.5 4 4.50
0.51
1.52
2.53
3.54
4.5
Scattergram to show the Correlation between variable
1 and variable 2
Titles are VERY important. Title your axis, the integers and give the graph a title.
y ax
is la
bel
y ax
is la
bel
x axis label x axis label
Levels of DataNominal - measure of central tendency: modeData in categories (finished, fell, started)
Ordinal - measure of central tendency: median Data which are ranked or in order (1st 2nd 3rd)
Interval / Ratio - measure of central tendency: mean
Precise and measured using units of equal intervals (1m54s, 1m59s, 2m03s)
Ratio has a definite and meaningful zero point
Cat
ego
rica
l C
on
tin
uo
us
TYPE DESIGN
NOMINALDATA
ORDINALDATA
INTERVALDATA
REPEATEDMEASURES Sign test Wilcoxon sign test
Related ttest*
MATCHEDPAIRS Sign test Wilcoxon sign test
Related ttest*
INDEPENDENTMEASURES Chi-squared
Mann-Whitney'U'
Unrelated ttest*
CORRELATION Chi-squaredSpearman
RhoPearsonmoment*
* For Parametric tests Parametric criteria must also be met.
20 minutes
• Must be able to describe (AO1) the observational method and its components.
• Must be able to evaluate (AO2) the observational method.
• Should be able to identify different data types (nominal, ordinal and interval/ratio).
It’s all about you …
Lesson ObjectivesBy the end of the lesson you …
• Must be able to design (AO3) an observation. • Should be able to carry out (AO3) an
observation to collect data.
Category 1 Category 2
SC1 SC2 SC3 SC1 SC2 SC3
Male
Female
Eating behaviour in the canteen Politeness in the canteen / around the college On task / off task behaviour …
• Must be able to design (AO3) an observation. • Should be able to carry out (AO3) an observation
to collect data.
