Danger of majority rule of collective intelligence

According to wikipedia, collective intelligence can be defined as " a shared or group intelligence that emerges from collaboration and competition of many individuals and appears in a wide variety of forms of consensus decision making" (Wikipedia).

I think this is one of the best methods that apply constructivism in teaching and learning environment. Because everyone can participate in both learning and teaching by sharing their knowledge.

However, I want to look at the weak point of this wonderful method. (Because I believe recognising weak points is the startingpoint of development for the better phase.)

Collective intelligence is supposed to make a decision which can be accepted and agreed to most of individuals in the group. That means the statement consented by majority of group would be decided as a truth.
Here is my question :
"What if only one person knows the truth and the rest of people believe their wrong answers are correct?"
Then the consensus would be made by the majority group with the belief "the more, the better". And the wrong statement would become a truth with the help of majority rule.

I have thought about this problem and these are my possible solutions.
People need to be critical about their understanding even though it is regarded as truth thanks to the consensus by many people. The hypothesis supported by many people does not necessarily mean that it's true.
And the person who is in minority group and strongly believes that his/her ideas are right should develop the belief enough to persuade the others rather than giving them up.

Then the collective intelligence can be validated and reliable qualitatively as well as quantitively.

Being a specialist blogger

Today is Monday, which is the last day before the weekly assignment.
I realise that I am quite passive in making my blog.
So I have decided to become an expert on blog creating from now on.
Because I am aware of the importance of computer technologies in teaching.
If I am reluctant to keep up with the changes of teaching tools, I will be stuck in my old habits.
That's why I have decided to change my attitudes towards technologies.
First of all, I will have my blog set as the home page on my laptop.
This will remind me every time when I turn on the laptop to create a new entry.
And I will write in my online diary about my journey of becoming a specialist blogger.
That can help me update new postings.
This is the promise that I have to make to myself.
I hope I will keep the promise and I'll be confident at blogging at the end of this semester.