How to Display Data- P14:The best method to convey a message from a piece of research in health is via a fi gure. The best advice that a statistician can give a researcher is to fi rst plot the data. Despite this, conventional statistics textbooks give only brief details on how to draw fi gures and display data. | Relationship between two continuous variables 57 If it is necessary to display the correlation between all pairs of a set of three or more variables thiscanbedone bymeansof acorrelationmatrix Table or the preferred graphical equivalent Figure . Regression The equation oftheregression line stiouldlie given togetherwith the r2 value or preferably the residual standard deviation. The number of observations n used to produce the regression equation should be staSid. Wherever possiilgthr rggtessiosligesnouldbeshown he gplot together with the sintterdiagramof the rawdaba wiliiSe gihUicSne esglanatoryj variable on the g-axisaodthe dependent variable on the Y-axis. The line should nod extend ag hgsSt rsdi-h ti ot ihepredidtosvnrSdhie txg. The standaad srror oh t ire etogoil uesdut as tsthe t-vaiue from She hypothesis destOfoi the stipe 0 The accuraayusedfor titi corifigienttihobld go ss iahrileo iteacoLisacy of the raw tpia. th morns no regoe to give Mt equition OhaS ptiposds to predict birtSlShetoya io iSeneartti ItlOOg when birthweight was actually measured tn sieeoroel goams. It is commeo tor tiia noloe oSihe esiimaieof tire interespeto gelatger than that of the sLopt hiil thets Msioeguent1yreocyteb do the itma number of gioimaiplgcts. baoweoeri when making predictions it is the slope thaS is noedggwitbmorepracisignootieas egtr ah rllkSbetaported at least as prtoieeIt or the ette rcehi. Method agree0 ítyht. Report n the nhmhoroipaigs dobtarboi. odh for method 1 and method 2. A scatter diagram of the measurements of method 1 vs. method 2 with a line of equaeity Y O ebu dbs produced. Preferably a mlgnd-Attman sthlereattee i-agram of egedrffrrenctgsSwoen the methods oo the eo-athevti eti gvel agegfbheiwgmethoda otiiht Y-axis shou bbepionuced. The Bland-AaOitoh stylescbSteddiageam shoeM ahnwlOelinr oSzsrodid-ference alonyaide ahs mean deffirenoe and tht i5 Emits oS tgreament Size of dots sOoakigo srLatihaSoems number of observations with that combinationof vahids. .
