Kwantitatieve Onderzoeksmethoden I
Week 1
1. Units
a. Rij
i. People, things etc.
2. Variables
a. Kolom
i. Age, eye colour etc.
Categorical Variable Numerical Variable
Binary Variable 2 Outcomes Discrete Variable Whole number
(Pass/fail a test) (10 people pass a test)
Nominal Variable +2 Outcomes, geen Continuous Variable Can in between 2
rangorde numbers
(Names, eye colour) (Temperature, length)
Ordinal Variable +2 Outcomes, wel een
rangorde
(Small, medium, large)
1. Measurement error
The disrepancy between the actual value and the number we use to represent.
(Weight actually 80KG, in de badkamer weeg je +3KG)
a. Systematic measurement error
(+2KG for everyone, calibrate the scale)
b. Random measurement error
Geen structuur. Soms een te hoge waarde en soms een te lage waarde, on average
correct.
(Ice skating multiple measurement systems to decide who is the winner)
Location:
Median The middle score when data is ordened
Mean (X̄) Sum of data divided by amount of data
Dispersion:
Range Smallest subtracted from the largest
IQR Interquartile range, Middle 50% of the data
(1 2 3 4 5 6 7 8 9 10 11)
(3 tot 6 = first quartile, 6 tot 9 = second quartile)
Variance Alex 175 cm -5 cm 25 cm2
Rob 185 cm +5 cm 25 cm2
Leo 180 cm 0 cm 0 cm
(25+25+0)/(3-1) = 25 cm2
Standard The square root of the variance
deviation
, Other:
95% Confidence interval of the mean (X̄-2(S/√N), μ, X̄+2(S/√N)
Positive skewness Right skewness (Vliegtuig)
Negative skewness Left skewness (Batterij)
Mode Most frequent score
Bimodal Two modes (man/vrouw)
Multimodal Several modes (medewerker A, B & C)
1 Variabele:
- Categorical variable Bar/Pie chart
- Numerical variable Histogram
Categorical Variable Numerical Variable
Categorical Variable Multiple bar chart =Boxplot
Numerical Variable =Boxplot Scatterplot
Week 1
1. Units
a. Rij
i. People, things etc.
2. Variables
a. Kolom
i. Age, eye colour etc.
Categorical Variable Numerical Variable
Binary Variable 2 Outcomes Discrete Variable Whole number
(Pass/fail a test) (10 people pass a test)
Nominal Variable +2 Outcomes, geen Continuous Variable Can in between 2
rangorde numbers
(Names, eye colour) (Temperature, length)
Ordinal Variable +2 Outcomes, wel een
rangorde
(Small, medium, large)
1. Measurement error
The disrepancy between the actual value and the number we use to represent.
(Weight actually 80KG, in de badkamer weeg je +3KG)
a. Systematic measurement error
(+2KG for everyone, calibrate the scale)
b. Random measurement error
Geen structuur. Soms een te hoge waarde en soms een te lage waarde, on average
correct.
(Ice skating multiple measurement systems to decide who is the winner)
Location:
Median The middle score when data is ordened
Mean (X̄) Sum of data divided by amount of data
Dispersion:
Range Smallest subtracted from the largest
IQR Interquartile range, Middle 50% of the data
(1 2 3 4 5 6 7 8 9 10 11)
(3 tot 6 = first quartile, 6 tot 9 = second quartile)
Variance Alex 175 cm -5 cm 25 cm2
Rob 185 cm +5 cm 25 cm2
Leo 180 cm 0 cm 0 cm
(25+25+0)/(3-1) = 25 cm2
Standard The square root of the variance
deviation
, Other:
95% Confidence interval of the mean (X̄-2(S/√N), μ, X̄+2(S/√N)
Positive skewness Right skewness (Vliegtuig)
Negative skewness Left skewness (Batterij)
Mode Most frequent score
Bimodal Two modes (man/vrouw)
Multimodal Several modes (medewerker A, B & C)
1 Variabele:
- Categorical variable Bar/Pie chart
- Numerical variable Histogram
Categorical Variable Numerical Variable
Categorical Variable Multiple bar chart =Boxplot
Numerical Variable =Boxplot Scatterplot
