4.3.1 Experimental design Flashcards
(31 cards)
case study
an investigation of an activity or problem specific to a real or hypothetical situation that includes many variables and complexities encountered in the real world
classification and identification
classification: organisation and categorisation of phenomena, objects, organisms in smaller more manageable groups
identification: recognising whether something belongs in an existing group or new unique group
controlled experiment
experiment investigating relationship between one independent variable and one dependent variable while ensuring all other variables are controlled
correlation study
planned observation and recording of events to find a relationship between variables that are not controlled
(DV linked to possible variables and analysed for amount of correlation)
fieldwork
observing and collecting data from natural environment outside of lab measuring effect of IV on DV but not controlling conditions
literature review
investigating question by collating and analysing secondary data to combine scientific findings from multiple sources
modelling
construction of physical, conceptual or mathematical representation used to simulate real world situation
simulation
using existing model to investigate change of variables when real system is too complex to manipulate variables
product, process, system development
using scientific knowledge, processes or technology to design product, process or system that meets human needs
independent variable
variable changed on purpose
dependent variable
quantified change in response to IV
controlled variable
kept constant in an experiment to ensure only IV affects DV
negative control group
group of samples not exposed to any value of IV to provide known level of DV without IV that experimental group can be compared to
aim
relationship between IV and DV you are trying to determine
- to determine how IV affects DV
hypothesis
educated and testable prediction of directional relationship between IV and DV
- it is predicted that as IV increase DV will increase/decrease as measured by
conclusion
directional relationship between IV and DV providing evidence to support/negate hypothesis, referencing validity
- it was found that as IV increased from __ DV in/decreased from __. this supports my hypothesis as DV significantly in/decreased. Validity was low/high
primary data
data generated by reseracher
secondary data
data collected by someone from another person’s or organisations research
provisional data
preliminary or incomplete data subject to revision
line graphs
continuous IV as we can predict values that fall between our data
bar graphs
bar graphs for discrete and qualitative IV as they display data as separate categories in separate columns
personal error
- cause: human mistake
- prevention: perform experiment correctly and take more care
- effect: large variation in data and outliers
random error
- cause: unpredictable and caused by chance
- prevention: conducting multiple trials and calculate average reduces impact and improves data accuracy
- effect: vary both direction inconsistently of true value (decreases precision)
- example: sampling error, rounding, inability to read instrument
systematic
- cause: predictable caused by inbuilt accuracy or observer bias
- prevention: recalibrate equipment and eliminate observer bias
- effect: vary in one direction consistently from true value (decreased accuracy)
- examples: observer bias, zero error etc.
