How do you choose a research topic?I intend to work on an application development project, but i am having trouble selecting a topic

First it is always best to focus on topics on your subject
of most interest to yourself, but within the parameters of the assignment.  What
questions do you, yourself have about the subject?  Exploring such questions will help
you focus and produce a more interesting research project.  It is important to see what
sources are available for a particular topic to help decide between
topics.

The less you know about the subject to begin with
the harder it will be to choose a topic.  If you have no idea where to begin, some
background reading will help. You might find doing some initial reading on a subject
using a general source like an encyclopedia such as wikipedia might help gain some
background in order to pick a topic, but don't rely too heavily on such a source for the
actual research portion of your project.   It is a good place to begin, but don't limit
yourself to such a source, and remember to check facts across a number of sources
especially when using the internet.  Also find sources near your reading level, cutting
and pasting isn't research and you will not gain an understanding of your topic  if you
cannot understand what you are reading.  Never quote or paraphrase information you do
not comprehend, it will produce low quality work.