How to influence effect of single vote on a like/dislike bar?

Question

I'm making a simple rating system, just like youtube has:

This works great if you have a big userbase, but it's too sensitive with just a few votes.
Say the first vote is down, no green bar will be displayed.
Or when you have two votes, with 1 downvote, results in a 50%

While this is the actual result, it's a bit too fragile. Are there any common methods to overcome this? I'm thinking of starting with stats like 10up/10down, that'll ease the influence of 1 vote, but that makes me start at 50% if no-one voted (now default is 100%).

I'd like a fair method, where one vote doesnt have to much influence? I'm the techy, I can work with a formula.

Edit, Extra info after some answers:
- I'm not expecting much votes in a small timewindow, therefore hiding the bar until X votes are placed doesn't have a preference.
- I'm not going to add 'x votes', I don't want to give away that we have a low amount of votes (for now)

Answer 1

An idea that I can think of is to show the thumbs up/down and replace the bar with a message saying something like "Cast your vote to see the results"

Let it display this message until you have reached your threshold and then just display the bar permanently.

This will help you avoid a fragile low-user voting system and will encourage more of your users to vote in the first place.

That's just my two cents.

Answer 2

Using a more dynamic scale (i.e. some kind of Likert scale) probably won't help you much because people tend to vote at the extremes anyways in a "like / dislike" question.

You may wish to hide the results from view until you have a sufficient number of responses that you feel comfortable displaying a mean for; many rating systems have this feature (iTunes, for example, won't show an average rating until ~5 users have given reviews or ratings).

Edit

After your edits, I'm not sure there is a good answer to your question. You expect a low number of votes, but don't want to "give away" the fact that there will be a low number of votes. You want to show an average but don't want to show an average that has a low number of votes. Perhaps you should use a different system (like a purely positive "Like") that you would feel more comfortable with.

Answer 3

You can make it like a point system from -2 to 7 for example. It could vary by your major content category. For a music sharing system with this point system I think a track with higher than 4 points in average is worth listening because, an average of 8 people from 10 are loving it.

I prefer this kind of dizzy numbering instead of the parallel ones (eg: -10 to 10) because you can add your own info and perspective on how people liked or disliked the material. -2 and -1 precisely mean "DISLIKE" and 7 means "LOVE" Then in your rating system you are free to make a hate-list by negative points or to make most-loved by 7s. You can even exclude negative points because there may be some users against some artist. I only mean the positive dynamics of an unfamiliar rating system.

Since your designed poll bar is great looking and I assume you finally will use it, I think a thicker green bar with a guiding level text (eg: low impression, people like it, Everyone loves it) line would make it nicer and more informative.