Sam, a newly admitted student, recently submitted a question about the role of minis in the curriculum. I thought it best to answer in a separate post, as it is likely that more people will see the answer this way.
First up, to Sam and all other admitted students for the Tuck Class of 2014 - a massive congratulations! You have a GREAT couple of years ahead of you!
Now, about minis. The Tuck curriculum is made up of a minimum of 82.5 credits; 46.5 credits in first year and 36 in second year. Core classes account for 40.5 of these, all taken in first year. If you exempt any core classes, you have to take electives in their place during your first year. A 'full' class is for three credits and typically meets for 18 sessions. A 'mini' class is half of that. There are five minis in the core curriculum (Analysis for General Managers, Leading Individuals & Teams, Leading Organizations, Personal Leadership, and Executive Communication) and you can take as many as you like in electives. Some classes (for example, Real Estate) are offered as either a full or a mini (in different terms) so students can decide how much depth they want to go into on the subject (none, some or a lot), but most are only offered as either a full or a mini. Generally speaking, minis are used where the course is reasonably confined in scope, either in breadth or in depth.
Minis can be first-half, second-half or full. That basically means they either meet for the first four and a half weeks of the term, the second four and a half weeks of term, or only meet once per week throughout the entire nine-week term. There is debate among students here about whether the volume of workload is higher in two minis or one full class; people have opinions both ways. I've experienced highly demanding minis and others with a lighter load, and the same is true of my experience of fulls so it's hard to generalize. For reasons unknown, my grades have been higher in minis than in fulls. This has nothing to do with how they are graded - I just seem to have been better at those classes. Overall, I try to balance my electives between fulls in which I can develop deep expertise or comprehensive knowledge of a topic, and minis, where I can expose myself to a wide range of topics in a short space of time.