I have been searching for free options of statistics analysis program. In a quick internet search, a few options have appeared (PAST, PSPP, R, etc). In your opinion, which is the best and most reliable program among the available options?
I suppose this really depends on the goals you wish to achieve through the use of these programs as well as which analysis you will be using.
Personally, I have only worked with PAST and R, (as well as SPSS although not free) so I will speak to those two only:
Learning curve/startup:
PAST= very simple layout with easily accessible menus. For beginners this is a very easy to learn program. Download is also simple with one file creating one desktop icon.
R= R is much more complex in this regard, and without a guidebook or introductory course could be daunting for beginners
Ease of access:
PAST= has a very simplistic layout with most of what you need found under the drop menus at the top, with analysis conducted by selecting the data in the sheet then simply clicking the desired analysis.
R= has many more options to choose from, but is not in this way crowded. Once you are used to the menu system and where your more used analysis are located, becomes easier over time.
Customization:
PAST= does not allow for detailed customization of output, which is one of the biggest drawbacks to PAST. Output customization is limited to mainly the size of text/lines, colors, and that's about it. Menu and analysis customization is also very limited.
R= R allows for customization through the use of individual coded programs, which can be shared and downloaded. This allows for a huge degree of potential customization compared to PAST, but the learning curve for this is rather steep.
Available Analysis:
PAST= personally PAST has most of the analysis that I utilize in my work (multivariate pottery analysis in archaeology), however things like rotation of data in PCA, etc must be done in a separate program (I use SPSS for this). Depending on which analysis you would like to utilize, PAST could be enough or far too little.
R= due to the customized coded programs in R, your access to customized analysis to your research goals is greatly increased. Personally I have yet to fully utilize this, but working with someone who is familiar with R should help.
Support:
PAST= for me, PAST does not have the largest user-base, and lacks in dedicated forums for questions you may have. The user-manual is also very basic, and does not go into great detail. When I have a problem with PAST, I find it (compared to R or SPSS), much more difficult to find an answer or troubleshoot. PAST requires more trial and error in this regard.
R= R has many dedicated forums to ask questions and receive feedback/share outputs. Usually you can find many answers to questions you might have.
Overall, for my day to day activities, when I don't care to fuss with too many bells and whistles, I usually choose PAST, as it can provide me with output quickly and simply. For a detailed output where I want to customize my experience, I would choose R, but only after I studied up a bit on exactly what I wanted to achieve.
Sorry about the long-winded answer, but I hope this helps!
If your use of these programs is strictly for those tests you mentioned alone, then I would stick with PAST as it is the easiest to use and allows for easy output (as I mentioned above). It seems perhaps you cannot see my full answer on mobile versions of researchgate (very strange), so please see the full version on the web version!
In regards to the acceptance by the scientific community.. these types of things really depend on your field, but I have personally never seen anyone scoff at someone for using a free software as opposed to a paid one. While many people may use SPSS, I've seen a trend of more people switching to open source formats such as R more and more recently.
I fully endorse Loftus' answer; he summarizes exactly my purpose with PAST: It's easy-to-use and I believe it is becoming a very mature software with few bugs, but it will never be a match for R when it comes to flexibility for advanced users.