Section 1.2: Measurement. Your Class Data ( dotplots ):. Questioning the Class Data:. Are the measurements valid ? - What would make them NOT valid? Are the measurements reliable ? - What would make them NOT reliable? Is there any bias in your data ?
- What would make them NOT valid?
- What would make them NOT reliable?
- What would create bias in this activity?
- Percentages of population versus number of people in population.
Scale stuck this morning and read a pound lower
EXAMPLE: Bathroom Scale
Scale always reads 3 pounds higher
- Example: When measuring everyone’s height, all rulers started at 1 inch, not 0 inches.
- A study is reliable if measurements are consistent!
- You want small variability (very little spread for your data).
- If possible, take the averages of measurement data to draw conclusions from!
-Is your blood pressure monitor a valid method for measuring your blood pressure? Explain.
- Does your BP monitor have a problem with reliability or bias? Explain.