I m studying visual analytics and i have a theoretical question about this topic.
My professor introduced this schema in him slide
For connect data to visualisation. Some topic is very easy to understand and regards the rappresentation of data, plot and other tool, other topic instead regards the "data" in particular the data reduction using algorithm like PCA.
I m not very clear why using PCA over the data for reduction some data that we want rappresent. Ad example, if i have dataset with all movie(it s just an example) with some attribute ad example
id,title,year,review, userReview ecc...
Where is the correlation of this data?Why i need apply a PCA for reduce big database and lose some of this components that I can visualize in some plot or schema that for me is important For example could be interesting see all best movie that have high average review, using PCA we just cluster user in different movie (i saw example on Iris database here: https://firstname.lastname@example.org/pca-principal-component-analysis-729068e28ec8 )
Anyone can clarify me?