When it comes to the issue about what's the better ways to evaluate the presentation in class, peoples’ opinion differs from person to person and culture to culture. Some people prefer to watch the recording by themselves as they always know what's the best effect they want and how to improve, while others may prefer to invited to discuss and give opinions. In my opinion, I prefer the latter one as it gives me a better understanding from different angles so I would dramatically improve myself via various advances they give me.
Admittedly, some attenders may just not so professional to provide some really reasonable advice. While others pay just offer some suggestions which are too hard to achieve. On the contrary, a recorder of the presentation can just be studied in detailed so the speaker may find every problem he has. While the fact is before lecturing in front of class, he may already have made a recorder which has been watched and improved several times. However, there do exist some problems which is hard find by himself and at the time he doesn't have an effective way on how to handle some specific problems which may easily be addressed by others.
On the contrary, lecturer can carefully select the people who have rich experience in presentation. Some audience may not pinpoint the severe problems existing in the show while others may just have attended hundreds of presentations or have actually won a fame for themselves just because their talented skills showing in their thoughtful speeches. Those people who have already have sufficient experience in presentations can spot the problem easily and can come up with various inspired ways on how to eliminate it. So, communication with these sagacious listeners can find the problems with ease and efficiency.
Additionally, profound understanding of how the presentation should be showed and arranged would be achieved by some discussion with the listeners. The listens are exactly the person who wants to listen and know some things showed by the presentation provider. So, even though the orator already made every parts of his presentation really perfect, failure can still be the result with the lack of communication with the audience who may not have a general knowledge of something as the lecturer expected. As a result, some parts the audience already known may stress too much, while others parts which should give attentions to may just leave with indifference. This problem can easily be solved by a thorough discussion with other attenders.
In conclusion, invite other audiences may be a better choice for the lecturer to find with problem with ease and efficiency and at the same time the specific needs of the audience.