RBA - MP1 Exam

observational and experimental

making observations with unmanipulated variables; making correlations

making observations with a manipulated variable; investigating cause and effects

changes one variable at a time

variable being manipulated

produces data necessary to support or refute hypothesis

aspects of the experiment kept the same

a variable that links the independent and dependent variable and could be affecting the outcomes

objects being experimented on; humans referred to as subjects

comparison, random assignment, controls / constants, replication

the experiment compares two or more treatments

using chance to assign treatments to groups

variables kept the same in an experiment

using enough experimental units in an experiment

any outcomes from the dummy treatment

researcher and subject are unaware of which treatment is which

entire group we want information about

collects data from every individual in the population

subset of individuals from population which we actually collect data from

choosing easy to reach individuals from the population

people decide whether to join the sample; creates bias since strong-opinioned people will only want to participate

every group of n individuals in population has an equal chance to be selected (hat method)

classify population into homogenous groups (strata) and take SRS of them

classify groups into heterogenous groups (geographically) and take SRS of all the clusters; cluster chosen must be used

randomly choose starting point in population and select every kth member

occurs when some members of the population could not be chosen

when participant of experiment cannot be reached or refuses to participate

the person asking questions could potentially affect data (systemic incorrect responses)

manner of question asked could potentially affect answer

shown in bar graphs, frequency / relative frequency tables, pie chart

shown in histograms, stem plots, dot plots, box and whisker plots

two categorical variables organized according to a row and column variable

using the "margins" of the data

average of the data (use x with bar from sample mean and fancy u for population mean)

midpoint of distribution when data is arranged smallest to largest

middle half of the data (Q3 - Q1)

minimum, Q1, median, Q3, maximum

IQR using quartiles and median; standard deviation using mean

measures average distance of observations from mean; calculated by finding average of the squared distances and taking square root (s for sample and fancy o for population)

when data values are concentrated on left and less values are on the right; mean is greater than median (dinosaur tail points right)

when data values are concentrated in right and less values on the left; mean is less than median (dinosaur tail points left)

when data values are centered; mean and median is the same