What's the difference between "Lying" and "Bullshitting"?

I was editing an essay written by one of my friends. As part of her assignment, she had to carry out an experiment on being a 'crap detector'. In this essay, she had to discuss what the signs were of when someone is lying. She had to also differentiate between 'lying' and 'bullshitting'. 'Bullshitting', by the way, is in the dictionary.

I think that "lying" is blatant deception. "Bullshitting" is often a softer form of deception. Mind you, some people use the term to call people on their lies. Following a discussion with some other friends, it came to light that some people see BS'ing on paper as different than verbal BS.

What are your thoughts? I'd like to hear from you.