I'm near to giving up.

half the data I have collected could not be used.

people simply didn't care.

they just anyhow filled up the questionnaires, promptly collected $10 and ran off.

yet i spent hours keying in the data.

mostly useless.

There's a suitable term for this. that's GIGO (Garbage In Garbage Out)

with such junk data, i could hardly squeeze out any results.

tried numerous ways to interpret the data till 4 am yesterday.

i remember who you are. yes, beware. you will always be in my heart.