...
We couldn't figure out how to use Ajax in time, so we didn't. Thus, while the page refreshes when the user himself puts a bid on the market, it doesn't refresh when other users put bids on the market. This is a potentially catastrophic usability issue, since using old market data can very easily lead to inconsistent pricing and misinformed decisions. Clearly, there was no incentive for us to avoid Ajax except that we couldn't figure it out.
Design Decision IIIIV: Yes, PHP and mySQL
We could figure out how to use PHP and mySQL in time, so we did. This meant that we could maintain user data on-line. This is obviously very important if the interface is actually used in real life, since a midnight exchange whose transactions are ephemeral is useless. The implementation was a little tricky, but definitely worth it.
...
Evaluation
We conducted a user test on Sunday, May 8th, 2011 at the MIT Student Center.
...