+ All Categories
Home > Documents > Lab 01 NOTES on Scientific Data and Graphs

Lab 01 NOTES on Scientific Data and Graphs

Date post: 13-Jul-2016
Category:
Upload: study-smarter
View: 218 times
Download: 1 times
Share this document with a friend
Description:
Scientific dataGraphingGeneral Biology
9
Lab 01 SCIENTIFIC DATA & GRAPHS LAB NOTES Define raw data. What are the steps to organize raw data? What can be done to help visualize data? What is the purpose of lab 01 – scientific data and graphs? Define average. Define median. INTRODUCTION: RAW DATA: Measurements collected during a scientific experiment. Unorganized data, which doesn’t tell you much about themselves. Steps to organize raw data: Enter data into a data table so you can find the information easily. Summarize them in statistical terms (range, mean, median, and std. Deviation) so it is easier to compare and contrast later. To help visualize data: turn data tables into charts or graphs. Makes it easier to spot trends or correlations in our data if they exist. PURPOSE Introduction to data organization, data descriptions, and data charts/ graph construction. OBJECTIVES: Organize data into tables and calculate statistical descriptors of the data Create graphs/ charts from given data sets Analyze data and interpret trends from various graphs. VOCABULARY: AVERAGE: A number that is calculated by adding quantities together and then dividing the total by the number of quantities. = & (& ) (& * (⋯(& , - MEDIAN: The “midpoint” value in a sorted list of values First rank all of the values in the data set from min. to max. for odd # values: the median = the value that lies in the middle of the sorted list of values.
Transcript
Page 1: Lab 01 NOTES on Scientific Data and Graphs

Lab01 SCIENTIFICDATA&GRAPHS LABNOTES

Definerawdata.Whatarethestepstoorganizerawdata?Whatcanbedonetohelpvisualizedata?Whatisthepurposeoflab01–scientificdataandgraphs?Defineaverage.Definemedian.

INTRODUCTION:

RAWDATA:Measurementscollectedduringascientificexperiment.Unorganizeddata,whichdoesn’ttellyoumuchaboutthemselves.

•Stepstoorganizerawdata:

• Enterdataintoadatatablesoyoucanfindtheinformationeasily.

• Summarizetheminstatisticalterms(range,mean,median,andstd.Deviation)soitiseasiertocompareandcontrastlater.

•Tohelpvisualizedata:

turndatatablesintochartsorgraphs.Makesiteasiertospottrendsorcorrelationsinourdataiftheyexist.

PURPOSE

Introductiontodataorganization,datadescriptions,anddatacharts/graphconstruction.

OBJECTIVES:

• Organizedataintotablesandcalculatestatisticaldescriptorsofthedata

• Creategraphs/chartsfromgivendatasets• Analyzedataandinterprettrendsfromvarious

graphs.VOCABULARY:

AVERAGE:Anumberthatiscalculatedbyaddingquantitiestogetherandthendividingthetotalbythenumberofquantities.𝐴𝑉𝐺 = &'(&)(&*(⋯(&,

-

MEDIAN:

The“midpoint”valueinasortedlistofvaluesFirstrankallofthevaluesinthedatasetfrommin.tomax.•forodd#values:themedian=thevaluethatliesinthemiddleofthesortedlistofvalues.

Page 2: Lab 01 NOTES on Scientific Data and Graphs

Lab01 SCIENTIFICDATA&GRAPHS LABNOTES

Definebargraph.DefineXYscatterplot.Defineindependentvariable.Definedependentvariable.Definequalitativevariable.Definequantitativevariable.Defineslope.

•foreven#values:themedian=theaverageofthetwovaluesthatlieinthemiddleofthesortedlistofvalues.

BARGRAPH:

Agraph/chartthatusesnarrowcolumnsofdifferentheightstoshowandcomparedifferentamounts.

XYSCATTERPLOT:

Agraphofplottedpointsthatshowtherelationshipbetween2setsofdata.

INDEPENDENTVARIABLE:Thevariableinafunctionalrelationwhosevalueisindependent,notaffectedbyothervariables.Thevariablethatismanipulatedinanexperiment.

DEPENDENTVARIABLE:

Thevariableinafunctionalrelationwhosevalueisdependentupon,orinfluencedbyanindependentvariable.Afactorwhosevaluechangeswhentheindependentvariableischanged.

QUALITATIVEVARIABLE:Categoricalvariables,arevariableswithnonaturalsenseofordering.Arenotmuchnumericalinnature.

Color,names,gender,etc.

QUANTITATIVEVARIABLE:Variablethataremeasuredonanumericscale.Numericalinnature

Ordinal,interval,ratioscales,height,weight,length,etc.

SLOPE:

TheratiooftheamountthatYincreaseasXincreasessomeamount.

𝑠𝑙𝑜𝑝𝑒 = 345637&

= 89

Page 3: Lab 01 NOTES on Scientific Data and Graphs

Lab01 SCIENTIFICDATA&GRAPHS LABNOTES

Defineoutlier.OrganizeDr.Lopez’sdataonHerculesbeetlesbodylengthsintoadatatable.Yourtableshouldincludethefollowingheadings:gender,bodylength(mm),andhornlength(mm).Definerange.

OUTLIER:Somethingthatissituatedawayfromorclasseddifferentlyfromamainorrelatedbody,statisticalobservationthatisnoticeablydifferentinvaluefromtheothersofthesample.

EXERCISES:ExerciseA:DataTables

ExcerptsformDr.Lopez’sfieldresearchnotesonHerculesbeetles(Dynastesherculues)inMexico.

StatisticalDescriptionofData:RANGE:

Page 4: Lab 01 NOTES on Scientific Data and Graphs

Lab01 SCIENTIFICDATA&GRAPHS LABNOTES

Definemean.Definestandarddeviation.Whatisthemin.amountofvariablesneededtodothestandarddeviationforadataset?Calculatetherange,mean,medianandstandarddeviationforbodylengthsforeachdateofDr.Lopez’sdataandorganizethemintoadatatable.

Theareacoveringtheupperandlowerlimitsonaparticularscale𝑅𝑎𝑛𝑔𝑒 = max 𝑣𝑎𝑙𝑢𝑒 − min 𝑣𝑎𝑙𝑢𝑒

MEAN(average):Anumberexpressingthetypicalvalueinasetofdata

𝑚𝑒𝑎𝑛 = 𝑆𝑢𝑚𝑜𝑓𝑎𝑙𝑙𝑣𝑎𝑙𝑢𝑒𝑠𝑖𝑛𝑑𝑎𝑡𝑎𝑠𝑒𝑡

#𝑜𝑓𝑣𝑎𝑙𝑢𝑒𝑠𝑖𝑛𝑑𝑎𝑡𝑎𝑠𝑒𝑡

STANDARDDEVIATION(Std.Dev.):Ameasureofhowvariablethevaluesinadatasetare.

𝑆𝑡𝑑𝐷𝑒𝑣 = (𝑥 − 𝑚𝑒𝑎𝑛)Q

(#𝑜𝑓𝑣𝑎𝑙𝑢𝑒𝑠𝑖𝑛𝑑𝑎𝑡𝑎𝑠𝑒𝑡 − 1)

Σ=summation;x=theindividualvaluesinthedataset.

• Min.#ofvaluestodostd.Dev.Mustbeat

least3.

Page 5: Lab 01 NOTES on Scientific Data and Graphs

Lab01 SCIENTIFICDATA&GRAPHS LABNOTES

Calculatetherange,mean,medianandstandarddeviationforthehornlengthsamongthemalebeetles.Whydoweoftenturndataintochartsorgraphs?Inamxyscatterplotwhatdoesthex-axisrepresent?Inanxyscatterplotwhatdoestheyaxisrepresent?

Standarddeviation:EXERCISEB:DATACHARTS/GRAPHS

• Oftenturndatatablesintochartsorgraphstoquicklycompareorcontrastourresults.

o x-axis(horizontal):Displaystheindependentvariables,factorsthatyoubelievetoinfluenceordetermineyourexperimentalresults.

o Y-axis(vertical):Displaysthedependentvariables,themeasurementsthatyourecordedinyourexperiments.

Page 6: Lab 01 NOTES on Scientific Data and Graphs

Lab01 SCIENTIFICDATA&GRAPHS LABNOTES

Whatarethetwomostcommonlyusedcharts/graphsinscience?GenerateabargraphshowingthemeanandmedianHerculesbeetlebodylengthfromDr.Lopez’sdata.Besuretoincludeatitle,axislabelsforbothaxes.Generateaseparatebargraphshowingthedailymeanandmedianbodylengthswiththedatesbeingtheindependentvariable.Besuretoincludealegendtoclearlyindicatehowtheseriesarerepresented.Whatarethe3essentialpartsofachart/graph?

• Thetwomostcommonlyusedcharts/graphin

science:• Bargraphs:

Forcategoricalvariables• XYscatterplots:

Forcontinuousvariables.

PartsofCharts/Graph:

• Chart/graphtitle:Titleshouldbedescriptivebutnotinterpretative.

Tellthereaderwhatthechart/graphisabout.

Page 7: Lab 01 NOTES on Scientific Data and Graphs

Lab01 SCIENTIFICDATA&GRAPHS LABNOTES

Whatisapositivetrend?Whatisanegativetrend?

• Axislabels:Axislabelstellyourreaderwhattheindependentanddependentvariablesareonthechart/graph,aswellaswhatistheunitofmeasurement.

• Legend:Providealegendonyourgraphwhenyouhavemorethanoneseries.Tellsyourreaderswhichbar(onbargraphs)ordots(onXYscatterplots)arerepresentingwhichgroupofdata.

EXERCISEC:TRENDSPOTTING

• Wheninterpretingdatathroughcharts/graphs,wecanoftenvisuallyseeatrendorcorrelationbetweentheindependentanddependentvariables.

• Positivetrend:upwardtrend

o Astheindependentvariable(x)increases,thedependentvariable(Y)increasesaswell

o Hasapositiveslope

• Negativetrend:Downwardtrend

Page 8: Lab 01 NOTES on Scientific Data and Graphs

Lab01 SCIENTIFICDATA&GRAPHS LABNOTES

Whatdoestheslopeofthetrendlineimply?OrganizeadatatablefromDr.Lopez’sdataonthemaleHerculesbeetles.Calculatethehorn-to-bodyratio.Andgraphbodylengthvs.Hornlengthanddrawtrendatrendline.Graphbody/lengthvs.Horn/bodyratioanddrawatrendline.WhatwerethemeanandmedianbodylengthofallHerculesbeetlesinDr.Lopez’sstudy?

o Astheindependentvariable(x)

increases,thedependentvariable(y)decreases.

o Hasanegativeslope.

• Theslopeofthetrendline,regardlessofbeingpositiveornegative,impliesthestrengthofthetrendbetweenthetwovariables.

o Thesteepertheslope,thestrongerthetrend.

o Ifthetrendlineisflatorbarelyhasaslope,thenthereisnocleartrendorthetrendisweakbetweenthetwovariables.

𝑚𝑒𝑎𝑛 = 𝑏𝑜𝑑𝑦𝑙𝑒𝑛𝑔𝑡ℎ𝑓𝑜𝑟𝑒𝑎𝑐ℎ𝑏𝑒𝑡𝑡𝑙𝑒

𝑡𝑜𝑡𝑎𝑙#𝑜𝑓𝑏𝑒𝑒𝑡𝑙𝑒𝑠 = 80.1𝑚𝑚

𝑚𝑒𝑑𝑖𝑎𝑛 = 73.4 + 72.2

2 = 72.8𝑚𝑚

Page 9: Lab 01 NOTES on Scientific Data and Graphs

Lab01 SCIENTIFICDATA&GRAPHS LABNOTES

Didthedailymeansandmediansforbodylengthsdiffersignificantlyfromoneanother?WhatwerethemeanandmedianhornlengthofallthemaleHerculesBeetlesinDr.Lopez’sstudy?Whatdoestherange&standarddeviationstellyouaboutDr.Lopez’sdataset?Wasthereatrendbetweenbodylengthandhornlengthamongstmalebeetles?Wasitstrong/weak?Positive/negative?Whatkindoftrendexistsbetweenbodylengthsandhorn-to-bodyratio?Arethetrendsthesame?

Yes,theydifferedsignificantly,rangefrodailymean=6.4mm.Therangefordailymedians=15.1mm.Thesebeetlesarenotverylarge∴1mmwillmakesignificantdifference.Mean=40.6mm,Median=39.8mm.Therangefordailymean=21.1mm,andformedian=22.4mm.∴hornlengthsaresignificantlydifferentfromoneanother.ThatthereisasignificantdifferencebetweenbodylengthandhornlengthsinHerculesbeetles.Overallthereisalargedeviationbetweenthelengthsamongthebeetles.Thedataisspreadoutoveralargerangeofvalues.Thereisaweak,positivetrendbetweenhornlengthandbodylength.Thereisanegative,strongtrendbetweenhorn-to-bodyratioandbodylength.Thetrendlinesareoppositeofeachother.


Recommended