Summarizing and presenting numerical data
Vanja Pupovac, Mladen Petrovečki · Biochemia Medica · 2011
Ab stra ctScien ti fi c hypot he sis and type of the stu dy de fi ne va riab les that ha ve to be mea su red.Mea su re men ts are de ter mi ned by four dis tin ct sca les of measu re me nt; no mi nal, or di nal, in ter val and ra tio, pro du ci ng two dis tin ct types of da ta: ca te go ri cal and nu me ri cal.Nu me ri cal da ta are usual ly sum ma rized and pre sen ted by dis tri bu tion, mea su res of cen tral ten den cy and dis per sion.For nor mal ly dis tri bu ted da ta, arit hme tic mean and stan da rd de viation are used.For da ta not nor mal ly dis tri bu ted, me dian wi th da ta ran ge (mi ni mum to maxi mum, in te rquar ti le ran ge or per cen ti le ran ge) and mo de are used.Com mon ly used gra ph types in des crip ti ve sta tis ti cs for nu me ri cal da ta pre sen ta tion are er ror bar and box-a nd-whis ker plo ts.Out lie rs are va lues that are nu me ri cal ly dis ta nt from the re st of the da ta and mu st be re cog ni zed.Key wor ds: da ta, nu me ri cal; da ta pre sen ta tion; sum ma ri zi ng da ta Re cei ved