Hi Hadas, Thank you for the reply. The test has been conducted previously before finalising the landmark points for other users. I suspect the raw bone data itself is unsatisfactory. The .obj files generated from PACS>MITK>MeshLab>IDAVLandmark to have problems.
Kind regards, Helmi On Tuesday, October 11, 2016 at 4:50:12 AM UTC+8, Hadas L. wrote: > > Hi, > > I would consider doing a short reliability test on five specimens for each > individual for the single point landmarks and the curves. This shouldn't > take long and will give you an idea as to whether the landmarks are > reliable or not. Ideally this should be done before adding the landmarks to > the data set. > > Sincerely, > Hadas > > On Sun, Oct 9, 2016 at 5:56 AM, Helmi Hadi <[email protected] > <javascript:>> wrote: > >> Dear Morphometricians, >> >> I have a weird problem and I was hoping someone could help me on this. >> >> I have the same CT bone (n=400) with 14 landmarks (2 Single point and 12 >> sliding) larndmarked in IDAV Landmark by three different individuals >> following a figure key table. Each individual landmarked 100+ different >> bones. The figure key table has the shape of the bone, with the landmark >> locations and the order of landmarking. All users were briefed by a single >> person (user1) on how to extract the bone and landmark. All three >> individuals were present throughout the entire procedure but the bone >> segmentation and landmarking process was conducted individually. >> >> When I combine all the data, I noticed that PC1 and PC2 graph has two >> clusters. The effect is about 55% (as detailed in the eigenvalues below) >> After further checking the classifiers in MorphoJ, the source of the >> clustering is one person (user1) landmarked it is slightly differently >> compared to the other two. I have checked the outliers tab and no glaring >> outliers exists. As the sample size is big, the curve seem to be quite >> normal. >> >> Eigenvalues % Variance Cumulative % >> 1. 0.01603351 55.674 55.674 >> 2. 0.00496222 17.230 72.904 >> 3. 0.00224594 7.799 80.703 >> 4. 0.00121085 4.204 84.907 >> 5. 0.00076858 2.669 87.576 >> ... >> >> How to interpret the results for this kind of data? Things which come to >> my mind are: >> >> 1. Maybe the bones for user1 are different compared to the other two >> users. >> Or >> 2. User1 thinks the landmark location slightly different compared to >> others. >> Or >> 3. User2 and 3 could not locate the landmark locations of user1. >> Or >> 4. The landmarks selected are unreliable. >> >> Ideally I would need few other people relandmark the entire set, but it >> is not possible to do it now. Can anyone help shed some light on what is >> the probable cause? Thank you. >> >> >> Kind regards, >> >> Helmi Hadi, PhD >> School of Health Sciences, Universiti Sains Malaysia, >> 16150 Kubang Kerian, Kelantan, MALAYSIA >> >> >> -- >> MORPHMET may be accessed via its webpage at http://www.morphometrics.org >> --- >> You received this message because you are subscribed to the Google Groups >> "MORPHMET" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> > > -- MORPHMET may be accessed via its webpage at http://www.morphometrics.org --- You received this message because you are subscribed to the Google Groups "MORPHMET" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
