Investigative Investigative

Process SkillsProcess Skills

Evelyn VisagEvelyn Visagéé

daanvisage@mweb.co.zadaanvisage@mweb.co.za

Copyright 2010Copyright 2010

Investigative Process Investigative Process SkillsSkills• Basic process skillsBasic process skills Observation, Observation,

measurement, using numbers, space/time measurement, using numbers, space/time relationships, classifying, communicating, relationships, classifying, communicating, recording/displaying data as well as inferring recording/displaying data as well as inferring (arriving at a conclusion) and predicting. This (arriving at a conclusion) and predicting. This is developed in Natural Science from primary is developed in Natural Science from primary school.school.

• Integrated skillsIntegrated skills such as identifying and such as identifying and controlling variables, interpreting data, controlling variables, interpreting data, operational definitions, application of theory, operational definitions, application of theory, forming hypotheses and experimenting are forming hypotheses and experimenting are normally only developed in your secondary normally only developed in your secondary school years.school years.

The Scientific MethodThe Scientific Method

• PlanningPlanning

• Obtaining evidenceObtaining evidence

• Analysis Analysis

• EvaluationEvaluation

• Communicate findingsCommunicate findings

AimAim

• We observe a Phenomenon (something in the We observe a Phenomenon (something in the natural/material world), using our senses or natural/material world), using our senses or machines that are basically extensions of our machines that are basically extensions of our senses. senses. or or

• We have a Problem that we need to solveWe have a Problem that we need to solve

Cake RecipeCake Recipe

• IngredientsIngredientsCake flourCake flour 500 ml500 mlEggsEggs 44SugarSugar 375 ml375 ml

MilkMilk 250 ml250 mlSaltSalt 2.5 ml2.5 mlCooking oilCooking oil 50 ml50 ml

Baking PowderBaking Powder 15 ml15 mlVanillaVanilla 5 ml 5 ml

METHODMETHOD

• Step 1: Heat the milk and cooking oilStep 1: Heat the milk and cooking oil

• Step 2: Beat the eggs and gradually Step 2: Beat the eggs and gradually add add the sugar.the sugar.

• Step 3: Sieve the flour and salt.Step 3: Sieve the flour and salt.

• Step 4: Add the flour, the milk and the Step 4: Add the flour, the milk and the egg mixture.egg mixture.

• Step 5: Add the vanilla…… Step 5: Add the vanilla……

Ask questionsAsk questions

• Was the flour responsible for the height of the cake?Was the flour responsible for the height of the cake?• Was the milk responsible for the height of the cake?Was the milk responsible for the height of the cake?• Were the eggs responsible for the height of the cake?Were the eggs responsible for the height of the cake?• Was the sugar responsible for the height of the cake?Was the sugar responsible for the height of the cake?• Was the vanilla responsible for the height of the cake?Was the vanilla responsible for the height of the cake?• Was the baking powder responsible for the height of the Was the baking powder responsible for the height of the

cake?cake?• Was the oil responsible for the height of the cake?Was the oil responsible for the height of the cake?• Was the mixing responsible for the height of the cake?Was the mixing responsible for the height of the cake?• Were the pans responsible for the height of the cake?Were the pans responsible for the height of the cake?• Was the oven responsible for the height of the cake? Was the oven responsible for the height of the cake?

PlanningPlanning

Find the VariablesFind the Variables

• Use the poster to “brainstorm”Use the poster to “brainstorm”

• Identify the a) Independent variable Identify the a) Independent variable b) b) Dependent variable/sDependent variable/s c) c) Fixed/Control variablesFixed/Control variables

HypothesisHypothesis

• Use the variables of the most promising question Use the variables of the most promising question to formulate a hypothesis.to formulate a hypothesis.

• Hypothesis- General statement on what you Hypothesis- General statement on what you expect to expect to find in the investigation.find in the investigation.

Educated guess. Educated guess. Answer to Answer to

the question.the question.• The hypothesis must be backed up Scientific The hypothesis must be backed up Scientific

evidenceevidenceThe The type of baking powdertype of baking powder

will change the will change the height of the cakeheight of the cake..

Scientific EvidenceScientific Evidence

• Find out more about your intended Find out more about your intended investigation. Preliminary work/knowledge?investigation. Preliminary work/knowledge?

• Read books, magazines or ask professionals Read books, magazines or ask professionals who might know in order to learn more who might know in order to learn more about the area of study.about the area of study. eg Baking eg Baking powder/chemical reactionpowder/chemical reaction

• Keep track of where you get your Keep track of where you get your information from (for reference purposes).information from (for reference purposes).

Fixed/Control VariablesFixed/Control Variables

• Use all the considerations of variables Use all the considerations of variables ( in the poster), to determine the most ( in the poster), to determine the most important fixed variables.important fixed variables.

• EgEg OvenOvenMixing toolMixing toolActual mixingActual mixing

PersonPerson

PredictionPrediction

• Very specific – what you expect to Very specific – what you expect to happen happen in this in this investigationinvestigation

“A cake baked with “A cake baked with Rosy’s Baking Powder will be higher Rosy’s Baking Powder will be higher than one baked with Mooring’s than one baked with Mooring’s Baking Powder” Baking Powder”

MethodMethod

• Discuss any preliminary workDiscuss any preliminary work

• Write down your method – step by Write down your method – step by stepstep

List of apparatus and List of apparatus and requisitesrequisites

• List means like a “shopping list”List means like a “shopping list”

• Include the blanc table – set up for Include the blanc table – set up for the chosen independent and the chosen independent and dependent variables.dependent variables.

• Don’t forget a clip board!Don’t forget a clip board!

SafetySafety

• Take into account and discuss all Take into account and discuss all safety measures to be taken into safety measures to be taken into account in the investigation.account in the investigation.

• EgEg electricity and glasselectricity and glass

Conducting Conducting the the

InvestigationInvestigation

Conducting the Conducting the InvestigationInvestigation• This means doing the actual experimentThis means doing the actual experiment

• Record all numerical (measured) or Record all numerical (measured) or observed data – in the tableobserved data – in the table

• Keep careful note of everything you do Keep careful note of everything you do and everything that happens.and everything that happens.

• Write down all problems that you have Write down all problems that you have encountered.encountered.

• Write your data in the table.Write your data in the table.

TableTable

• Heading Heading A table to show the A table to show the relationship relationship between the between the ((dependent variabledependent variable)) and theand the ((independent variableindependent variable))

• Column headings Column headings Independent variable Left-hand sideIndependent variable Left-hand sideDependent variable/s Right-hand sideDependent variable/s Right-hand side

• SI units: / or ( )SI units: / or ( )• Arrange data of the independent variableArrange data of the independent variable

A table to show the relationship between the A table to show the relationship between the type of baking powder and height of the cake.type of baking powder and height of the cake.

Type of Baking Type of Baking PowderPowder

Height of Cake (mm)Height of Cake (mm)

AnalysisAnalysis

AnalysisAnalysis

• Look for a pattern (relationship) between Look for a pattern (relationship) between the variables/data in the table – ie the variables/data in the table – ie between the between the ((dependent variabledependent variable)) and and thethe ((independent variableindependent variable))..

• Decide on a suitable graphDecide on a suitable graph• Draw/plot the graph Draw/plot the graph • Describe the pattern – between the Describe the pattern – between the

((dependent variabledependent variable)) and theand the ((independent variableindependent variable))

The GraphThe Graph

• Pie ChartPie Chart• Line/curved graphLine/curved graph• Scatter graphScatter graph• Bar chartBar chart• HistogramHistogram• Column graphColumn graph

Advanced levels of experimental science Advanced levels of experimental science rely heavily on graphical and rely heavily on graphical and mathematical analysis of the datamathematical analysis of the data

Pie ChartPie Chart

• Pie charts are drawn with the sectors Pie charts are drawn with the sectors (slices of the pie) in rank order, (slices of the pie) in rank order, largest first, beginning at “noon” and largest first, beginning at “noon” and proceeding clockwise. Pie charts proceeding clockwise. Pie charts should preferably contain no more should preferably contain no more than six sectors.than six sectors.

Bar chartBar chart

• Bar charts are drawn when the Bar charts are drawn when the independent variable does not have independent variable does not have a numerical value e.g. the number of a numerical value e.g. the number of learners with blue, brown, hazel and learners with blue, brown, hazel and black eyes in a class.black eyes in a class.

• How to draw a bar chart:How to draw a bar chart:• Bar charts are made up of data blocks or bars of equal Bar charts are made up of data blocks or bars of equal

width. These bars width. These bars do notdo not touch each other. The spaces touch each other. The spaces between the bars must also be of equal width, although between the bars must also be of equal width, although they are normally much narrower than the bars. There is they are normally much narrower than the bars. There is always a space between the first bar and the y-axis.always a space between the first bar and the y-axis.

• The independent variable is plotted on the x-axis and the The independent variable is plotted on the x-axis and the dependent variable on the y-axis.dependent variable on the y-axis.

• The axes should be fully labelled. Add appropriate units on The axes should be fully labelled. Add appropriate units on the y-axis with brackets, a slash or solidus. There could be the y-axis with brackets, a slash or solidus. There could be no units for the x-axis as there are no numerical values. no units for the x-axis as there are no numerical values.

• There must be a heading to explain what the bar chart There must be a heading to explain what the bar chart shows. The heading must contain both the dependent and shows. The heading must contain both the dependent and independent variablesindependent variables

HistogramHistogram

• When the independent variable is numerical and continuous When the independent variable is numerical and continuous from one extreme value to the other, you should draw a from one extreme value to the other, you should draw a histogram. The data is grouped into categories. Mass, length histogram. The data is grouped into categories. Mass, length and shoe size of learners in a class is a good example. In the and shoe size of learners in a class is a good example. In the case of mass, you would start with the group of learners that case of mass, you would start with the group of learners that have the smallest mass and end with the group of learners that have the smallest mass and end with the group of learners that have the highest mass.have the highest mass.

• How to draw a histogram:How to draw a histogram:• The categories or independent variable is plotted on the x-axis, The categories or independent variable is plotted on the x-axis,

as bars. as bars. • The number of bars is determined by the number of categories The number of bars is determined by the number of categories

into which you group your data. Choosing the categories is very into which you group your data. Choosing the categories is very important as your aim is to see a pattern. If there are too many important as your aim is to see a pattern. If there are too many categories it might be difficult to see the pattern. A rule for categories it might be difficult to see the pattern. A rule for determining the number of categories is to take five times the determining the number of categories is to take five times the log of the total number of observations. Use your calculator to log of the total number of observations. Use your calculator to work this out.work this out.

• The bars of a histogram should be of equal width and touch each The bars of a histogram should be of equal width and touch each other. The first bar should start against the y-axis.other. The first bar should start against the y-axis.

• Choose an appropriate scale and mark out the x-axis, showing Choose an appropriate scale and mark out the x-axis, showing the edges of each data block. Label each bar with the the edges of each data block. Label each bar with the appropriate range of values.appropriate range of values.

• Label the x-axis and add appropriate units with brackets, a Label the x-axis and add appropriate units with brackets, a slash or solidus.slash or solidus.

• The dependent variable is plotted on the y-axis. In a histogram The dependent variable is plotted on the y-axis. In a histogram it always represents the number or frequency.it always represents the number or frequency.

• Label the y-axis. Add appropriate units with brackets, a slash Label the y-axis. Add appropriate units with brackets, a slash or solidus.or solidus.

• There must be a heading to explain what the histogram shows. There must be a heading to explain what the histogram shows. The heading must contain both the dependent and The heading must contain both the dependent and independent variables. A histogram to show the relationship independent variables. A histogram to show the relationship between the (dependent variable) and (independent variable).between the (dependent variable) and (independent variable).

• The heading, axis’s, labels and units are written/drawn in The heading, axis’s, labels and units are written/drawn in black/blue ink. The bars are drawn in pencil and then shaded black/blue ink. The bars are drawn in pencil and then shaded or colouredor coloured

Column GraphsColumn Graphs

• Column graphs are drawn when Column graphs are drawn when plotting frequency graphs from plotting frequency graphs from discrete data, e.g. frequency of discrete data, e.g. frequency of occurrence of leaves with different occurrence of leaves with different numbers of prickles or pods with numbers of prickles or pods with different numbers of seeds.different numbers of seeds.

Line graphLine graph

• We often plot line graphs in Science! Both dependent and We often plot line graphs in Science! Both dependent and independent variables have numerical values.independent variables have numerical values.

• How to draw a line graph:How to draw a line graph:• The independent variable will be plotted on the x-axis The independent variable will be plotted on the x-axis

(horizontal) and the dependent variable on the y-axis (vertical). (horizontal) and the dependent variable on the y-axis (vertical). Consider the values and their position on the Cartesian Consider the values and their position on the Cartesian planeplane. Draw them in blue/black ink. Use as much of your graph . Draw them in blue/black ink. Use as much of your graph paper/available space as possible. Work out appropriate scales paper/available space as possible. Work out appropriate scales for each axis. Mark every section with a small pencil line. We for each axis. Mark every section with a small pencil line. We often change our scale while deciding on the value of sections. often change our scale while deciding on the value of sections. If done by pencil one can easily alter it. After you have finalised If done by pencil one can easily alter it. After you have finalised the scale, write the values at every small pencil line with pencil. the scale, write the values at every small pencil line with pencil. Remember – your scale must add/go up in equal amounts, Remember – your scale must add/go up in equal amounts, forming each section. It must accommodate the lowest and forming each section. It must accommodate the lowest and highest value for each variable.highest value for each variable.

• Label each axis with the name of the physical quantity and the Label each axis with the name of the physical quantity and the appropriate SI unit e.g Time/s or Time (s).appropriate SI unit e.g Time/s or Time (s).

• Points are plotted and clearly marked by crosses (x) or Points are plotted and clearly marked by crosses (x) or encircled dots (o). Use the finest, sharpest, hardest pencil encircled dots (o). Use the finest, sharpest, hardest pencil you can find (2H or harder). Precision in this activity is of you can find (2H or harder). Precision in this activity is of the utmost importance. Your teacher/examiner checks the utmost importance. Your teacher/examiner checks these points when marking your graph. Plot all the points these points when marking your graph. Plot all the points first. You then have to carefully check and consider what first. You then have to carefully check and consider what the graph will look like once the points are joined. The the graph will look like once the points are joined. The graph is the whole diagrammatic presentation of your data. graph is the whole diagrammatic presentation of your data. Do you see any curves or do the plotted points lie in a Do you see any curves or do the plotted points lie in a straight line? If there is a clear straight line (ie your values straight line? If there is a clear straight line (ie your values are directly proportional), join the points with a ruler. If the are directly proportional), join the points with a ruler. If the points indicate a curve, do not join them with a ruler. Join points indicate a curve, do not join them with a ruler. Join them by free hand. Use a thin, sharp, hard pencil. No points them by free hand. Use a thin, sharp, hard pencil. No points must be plotted or joined with a pen, fibre tip pen or must be plotted or joined with a pen, fibre tip pen or colouring pencilcolouring pencil..

• It may also well be that the plotted points lie in It may also well be that the plotted points lie in what looks more or less (around) a straight line. what looks more or less (around) a straight line. This is a special type of graph, commonly found in This is a special type of graph, commonly found in Physics. It is called a scatter-graph. You draw a Physics. It is called a scatter-graph. You draw a line that best fits all the points with a ruler (if it line that best fits all the points with a ruler (if it looks like a straight line) and a curve if all the the looks like a straight line) and a curve if all the the points together seems like they are forming a points together seems like they are forming a curve.curve.

• Label each axis with the name of the physical quantity and Label each axis with the name of the physical quantity and the appropriate SI unit e.g Time/s or Time (s). the appropriate SI unit e.g Time/s or Time (s).

• Points are plotted and clearly marked by crosses (x) or Points are plotted and clearly marked by crosses (x) or encircled dots (o). Use the finest, sharpest, hardest pencil encircled dots (o). Use the finest, sharpest, hardest pencil you can find (2H or harder). Precision in this activity is of the you can find (2H or harder). Precision in this activity is of the utmost importance. Your teacher/examiner checks these utmost importance. Your teacher/examiner checks these points when marking your graph. Plot all the points first. You points when marking your graph. Plot all the points first. You then have to carefully check and consider what the graph will then have to carefully check and consider what the graph will look like once the points are joined. The graph is the whole look like once the points are joined. The graph is the whole diagrammatic presentation of your data. Do you see any diagrammatic presentation of your data. Do you see any curves or do the plotted points lie in a straight line? If there is curves or do the plotted points lie in a straight line? If there is a clear straight line (ie your values are directly proportional), a clear straight line (ie your values are directly proportional), join the points with a ruler. If the points indicate a curve, do join the points with a ruler. If the points indicate a curve, do not join them with a ruler. Join them by free hand. Use a thin, not join them with a ruler. Join them by free hand. Use a thin, sharp, hard pencil. No points must be plotted or joined with a sharp, hard pencil. No points must be plotted or joined with a pen, fibre tip pen or colouring pencil.pen, fibre tip pen or colouring pencil.

• It may also well be that the plotted points lie in It may also well be that the plotted points lie in what looks more or less (around) a straight line. what looks more or less (around) a straight line. This is a special type of graph, commonly found in This is a special type of graph, commonly found in Physics. It is called a scatter-graph. You draw a Physics. It is called a scatter-graph. You draw a line that best fits all the points with a ruler (if it line that best fits all the points with a ruler (if it looks like a straight line) and a curve if all the the looks like a straight line) and a curve if all the the points together seems like they are forming a points together seems like they are forming a curve.curve.

• Points are plotted and clearly marked by crosses (x) or Points are plotted and clearly marked by crosses (x) or encircled dots (o). Use the finest, sharpest, hardest encircled dots (o). Use the finest, sharpest, hardest pencil you can find (2H or harder). Precision in this pencil you can find (2H or harder). Precision in this activity is of the utmost importance. Your activity is of the utmost importance. Your teacher/examiner checks these points when marking teacher/examiner checks these points when marking your graph. Plot all the points first. You then have to your graph. Plot all the points first. You then have to carefully check and consider what the graph will look carefully check and consider what the graph will look like once the points are joined. The graph is the whole like once the points are joined. The graph is the whole diagrammatic presentation of your data. Do you see any diagrammatic presentation of your data. Do you see any curves or do the plotted points lie in a straight line? If curves or do the plotted points lie in a straight line? If there is a clear straight line (ie your values are directly there is a clear straight line (ie your values are directly proportional), join the points with a ruler. If the points proportional), join the points with a ruler. If the points indicate a curve, do not join them with a ruler. Join them indicate a curve, do not join them with a ruler. Join them by free hand. Use a thin, sharp, hard pencil. No points by free hand. Use a thin, sharp, hard pencil. No points must be plotted or joined with a pen, fibre tip pen or must be plotted or joined with a pen, fibre tip pen or colouring pencil.colouring pencil.

Scatter-graphScatter-graph

• It may also well be that the plotted points lie in It may also well be that the plotted points lie in what looks more or less (around) a straight line. what looks more or less (around) a straight line. This is a special type of graph, commonly found in This is a special type of graph, commonly found in Physics. It is called a scatter-graph. You draw a Physics. It is called a scatter-graph. You draw a line that best fits all the points with a ruler (if it line that best fits all the points with a ruler (if it looks like a straight line) and a curve if all the the looks like a straight line) and a curve if all the the points together seems like they are forming a points together seems like they are forming a curve.curve.

EvaluationEvaluation

EvaluationEvaluation

• Carefully consider the results obtained in Carefully consider the results obtained in your investigation.your investigation.

• Do they support your Hypothesis?Do they support your Hypothesis?

• Consider the equipment and methodology.Consider the equipment and methodology.

• Summarise any difficulties or problems you Summarise any difficulties or problems you had doing the experimenthad doing the experiment

• Were your readings/observations accurate Were your readings/observations accurate enough?enough?

• Were there any anomalous results? DiscussWere there any anomalous results? Discuss

• Do you need to change the Do you need to change the procedure and repeat the procedure and repeat the experiment?experiment?

• What would you do different next What would you do different next time?time?

• List other things you have learned.List other things you have learned.

Related questionsRelated questions

• You may be able to answer some of You may be able to answer some of the other questionsthe other questions

• Several new questions may have Several new questions may have occurred to you while doing the occurred to you while doing the investigation.investigation.

• Questions lead to more questions Questions lead to more questions which lead to additional hypothesis which lead to additional hypothesis that need to be tested.that need to be tested.

Accept/Reject HypothesisAccept/Reject Hypothesis

Make Make recommendations for recommendations for further researchfurther research

Evelyn Evelyn

VisagVisagéédaanvisage@mweb.co.zadaanvisage@mweb.co.za

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