What do you do with a presentation team that fails to prepare?

I just finished a presentation "rehearsal" meeting with a group of 4 students who are on the same team to prepare a presentation for my academic reading/writing class. The team was created over a month ago, and this afternoon is the presentation time, but they still have very little prepared. No visuals, no organized argument, very little research to support what they seem to be arguing.

Ahhh! Makes me want to scream, mainly because I don't know what to do with them. I was about to say "Get out of here and don't waste my time" because I can't really give any advice unless a presentation is more or less prepared. I also was tempted to say "You can't present" because the whole class is going to have to endure a sloppy production. But of course, being the kind, helpful teacher that I am, I listened to them stumble through a completely fragemented and incoherent presentation that showed no coordinator or thought on their part and then let them know that they need to figure out a thesis and organize their presentation around it--in 2 hours.

All other groups have created an interesting and organized presentation about a global issue and solutions for it. The team presentation at the end of the year is a requirement in my course and is 20% of the evaluation. Doing at least a satisfactory effort to present the problem and possible solutions is an important part of finishing the course. In the past, I have never had a group fail to prepare to this extent.

So...what went wrong?

One problem was how the team was formed. The students had a sign up system to get together with people of the same interest. The four students, who all tend to have relatively low attendance (but not low aptitude), were the last to sign up and ended up getting stuck with each other. Because of absence problems and generally low engagement by all of them, they were rarely all in attendance and could not agree on a topic or outline or other requirements. To some extent, I knew they would have trouble, but I didn't expect they would struggle this badly.

Also, perhaps I should have set a stricter minimum preparation requirement for allowing the rehearsal and presentation. Something to the effect of: If you don't have a topic, thesis, and visual materials by this date, your team will lose its right to make a presentation. Would that be effective? Possibly, but not necessarily if they really struggle to put things together.

But do you give those students a "0" score for the presentation then? Or, perhaps an alternative is to say they must find a video camera, tape their presentation and submit it. In any case, if they are not prepared, the other groups in the class should not have to suffer through 15 minutes of unprepared communication.

Another possibility is to dismantle the team and ask for individual presentations at a lower evaluation. They can't work as a team, so show me what you can do individually (on video?).

Why couldn't they communicate with each other outside class and move the presentation preparation forward? I want to ask them when they do their self-reflection. I hope I never have a team end up like this.

But who knows? They may put together something doable in two hours final preparation? I will keep my hopes.

Mark