Experimental Data

Experimental DataExperimental Data

The Nature of dataThe Nature of data

bData is the outcome of observation andmeasurementbData is the outcome of observation andmeasurement

bData may be acquiredbData may be acquired

êIn the fieldêIn the field

êBy experimentêBy experiment

What is an experiment?What is an experiment?

bData acquired under controlled conditionsbData acquired under controlled conditions

bExperiments involvebExperiments involve

êIdentifying relevant (key) variablesêIdentifying relevant (key) variables

êDeciding on which variables are to be manipulated(controlled)êDeciding on which variables are to be manipulated(controlled)

êDeciding on methods of measurementêDeciding on methods of measurement

êObtaining and using suitable equipmentêObtaining and using suitable equipment

Processing the data obtained.Processing the data obtained.

ReproducibilityReproducibility

bExperimental data should be reproduciblebExperimental data should be reproducible

êObservations made under the same conditionsshould lead to the same findings.êObservations made under the same conditionsshould lead to the same findings.

bNatural variability (ie. error) to be takeninto accountbNatural variability (ie. error) to be takeninto account

êCannot always reproduce conditions exactly.êCannot always reproduce conditions exactly.

êStatistics used to determine acceptable variationêStatistics used to determine acceptable variation

Types of dataTypes of data

The nature of data varies; based onThe nature of data varies; based on

bthe aims of the experimentbthe aims of the experiment

bthe nature of the phenomena investigatedbthe nature of the phenomena investigated

bMethods of data collectionbMethods of data collection

ActivityActivity

bHow would you collect data from/for:bHow would you collect data from/for:

êPreparation of new chemical compound?êPreparation of new chemical compound?

êExamination of bacterial culture?êExamination of bacterial culture?

êInvestigation of link between body temperature &time of death?êInvestigation of link between body temperature &time of death?

êInvestigation of links between diet & health?êInvestigation of links between diet & health?

Possible SolutionPossible Solution

bChemical analysis of productsbChemical analysis of products

bCount or identification of cellsbCount or identification of cells

bTemperature vs time databTemperature vs time data

bSurvey (Questionnaire) of target populationbSurvey (Questionnaire) of target population

Types of dataTypes of data

Fitness for purposeFitness for purpose

bThe nature of the data depends on thehypothesis being tested.bThe nature of the data depends on thehypothesis being tested.

bThe same phenomenon may be investigatedfrom a variety of viewpoints.bThe same phenomenon may be investigatedfrom a variety of viewpoints.

ActivityActivity

bWhat type of data would you require if youwere investigating a chemical reaction for:bWhat type of data would you require if youwere investigating a chemical reaction for:

êReaction sequence?êReaction sequence?

êStructure of product?êStructure of product?

êKinetics (rate) of the reaction?êKinetics (rate) of the reaction?

Possible SolutionPossible Solution

bAnalysis of compounds present at eachstagebAnalysis of compounds present at eachstage

bInformation on position of atoms within themoleculebInformation on position of atoms within themolecule

bQuantity of materials present over timebQuantity of materials present over time

Experimental PlanningExperimental Planning

bDecide on the purpose of your experimentbDecide on the purpose of your experiment

bRead the literature for previous workbRead the literature for previous work

bDevise a suitable experimental procedurebDevise a suitable experimental procedure

bAssemble your equipmentbAssemble your equipment

bMake measurementsbMake measurements

bAnalyse results & draw conclusionsbAnalyse results & draw conclusions

And Finally . . .And Finally . . .

bReview your findingsbReview your findings

bStart again!!bStart again!!

The EndThe End

For nowFor now