Reasons for changing your search string based on your results...

Reason #1

You didn't find enough information.  Maybe you didn't find ANY information!

It's possible that your search string is too specific.

How to change your search string:

Option 1 Go back to your brainstormed words and find more general keywords to substitute into your search string.  You will see two examples below.  In the first one, we have substituted the more general term media for (television OR TV).  In the second example, we have used the more general keyword education instead of "brain activity" which is very specific indeed. media AND child* AND "brain activity" or (television OR TV) AND child* AND education

Option 2 Another method of making your search more general is to drop a keyword from your search string.  Below, we have removed "brain activity" so that we are left with only the concepts television and children. (television OR TV) AND child*

Reason #2

You found too much information. And maybe none of it is focused enough to be useful.

. . .

It's possible that your search string is too general.

How to change your search string:

Option 1 Try adding more keywords.  Below we have added learning which helps us to focus more on the aspect of the topic we are interested in.    (television OR TV) AND child* AND "brain activity" AND learning

Option 2 Another technique for making your search more specific is to remove words joined with OR, since OR expands your search (OR is MORE, remember?).  Below, we have removed the term TV and left the keyword television.   television AND child* AND "brain activity"

Option 3 Finally, what about the asterisk?  Doesn't it help us retrieve multiple words with a single keyword?  If we removed the asterisk, that might also help us retrieve fewer results, if getting too many results is the main problem.  In the example below, notice that we have replaced child* with children.    (television OR TV) AND children AND "brain activity"

Phew!  Does this seem like hard work?    Don't worry, you probably won't ever need to do ALL of these things, but we wanted to show you all the options just in case you ever need them.