assessing reliability&validity (1 Viewer)

[dzzlng_07]

i know what the definitions of reliability and validity are.. but i dont know how to assess/evaluate the reliability and validity of a secondary source. also, last year, the teachers commented that i need to give "examples" to support my answer... what are they looking for? quotes?

can anyone help me out? im so lost

 

[twilight1412]

sorry but im gonna have to refer you to the other thread you made in physics since its pretty much the same thing

http://community.boredofstudies.org/263/space/129516/assessing-reliabilty-validity-secondary-source.html

 

[sykeout]

i know what the definitions of reliability and validity are.. but i dont know how to assess/evaluate the reliability and validity of a secondary source. also, last year, the teachers commented that i need to give "examples" to support my answer... what are they looking for? quotes?

can anyone help me out? im so lost

ok so reliability is the ability to repeat the prac a number of times, and get similar results.
Validity is how close the final calculations/conclusions come to scientific values and proved theories.
So to assess/evaluate results in a table or something, look for scientific value given in question or on data sheet & compare it to results, and for reliability, check if the numbers are all pretty close.

What i would like to know is...
for the molar heat of combustion prac, to asses the validity.. do i just say that its not very valid because its way off the scientific value for ethanol... and this could be due to loss of heat in apparatus and the surrounding atmosphere???

is there anything else to add??? im confusd.

 

[Lucid Scintilla]

ok so reliability is the ability to repeat the prac a number of times [repeatability], and get similar results.

I'll say yeah, whatever.

Validity is how close the final calculations/conclusions come to scientific values and proved theories.

No, how close your "calculations/conclusions" come to "scientific" (accepted) values '"and proved^{[sic - it's 'proven', an adjective]} theories"' is more related to accuracy than validity.

What i would like to know is...
for the molar heat of combustion prac, to asses the validity.. do i just say that its not very valid because its way off the scientific value for ethanol... and this could be due to loss of heat in apparatus and the surrounding atmosphere???

is there anything else to add??? im confusd.

No (not entirely; accuracy is related to your validity; precision, reliability), it's inaccurate, not "not very valid". (Sort of yes, actually.)

As for the discussion as to why it isn't the accepted, hypothetical values, yes; you talk about where the enthalpy's lost (incomplete combustion, adding initial activation energy, etc.), suggest how to improve your result (insulation of calorimetry vessel, stirring, wind shield, etc., and using - no duh - accurate apparatus).

See:
Accuracy and precision
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