and we talk about that as the post-purchase evaluation.
Well, just because I've formed that opinion internally,
doesn't mean that I care enough to express that opinion.
That's concerned with the opinion expression stage.
So my post purchase evaluation is going to drive my decision to post yes or no.
It's also going to drive what I post.
In this case, is it going to be positive?
Is it going to be negative?
Now, my internal opinion
isn't the only thing that's going to drive the opinion that I choose to express.
The opinion that I choose to express is also going to be driven
by what other people have said previously.
And so there might be a selection effect where previously posted ratings
affect my decision to even participate in the conversation.
Maybe I have an opinion that I'd like to share, but everyone else has said what I
would say, and I have nothing new to add to the conversation, so
I decide that I'm not going to participate.
Or perhaps, there's too much dissention in the previous comments,
and I don't want to deal with any conflict, so I decide not to participate.
All right, so that would be the selection effect.
The adjustment effect that we're concerned with is that previous ratings may lead me
to actually alter the opinion that I hold in terms of when I choose to express it.
So I might think that the product was the best thing ever, but
other people are negative about it.
All right, well, maybe that's going to cause me to temper my enthusiasm for
it a little bit.
I might go the other way, though.
Maybe I have a negative opinion and other people are also negative.
And I say, well, maybe it wasn't as bad as I really thought it was,
so maybe I'm going to boost it up a little bit.
This has been documented in terms of bandwagon effects.
It's actually one of the reasons why the results of elections on
the East Coast don't get reported until after polls close on
the West Coast in the United States because we don't want the earlier
decisions that people have made to affect later decisions.
And so one of the reasons why we run into potential problems
looking at user generated content as a gauge for
how much people like a product potentially is who
are the people who are ultimately contributing the comment?
Most of who we see, it's going to people who have a strong opinion.
If you really like the product, you're more prone to contribute a comment.
If you really dislike the product, you're probably going to say something about it.
But everyone who's kind of got that moderate opinion,
they're somewhere in the middle, they might lean toward liking it but it's not
a strong enough motivation for them to go online and say something about it.
Those people in the middle are actually less likely to express an opinion online.