LS15 ACTUAL CERTIFICATION PAPER
2026 QUESTIONS WITH ANSWERS FULL
SOLUTION.
⩥ what does a "critical experiment" do.Ans: put a hypothesis to the test,
the results can decisively determine whether a hypothesis is correct
⩥ class examples of scientific method.Ans: - does it rain more on
weekends?
- real vs artificial vanilla
- "maze bright" vs "maze dull" rats
⩥ class example: does it rain more on weekends? Ans: - find average
Monday and Saturday rainfall; rains 22% more on Saturdays
- hypothesis: particular matter from car exhaust builds up during the
week leading to cloud formation and then rain on the weekends
- experiment: collect data from somewhere with no cars (ocean)
- results: there is equal rainfall on each day in the ocean, PROVING that
car exhaust affects the trend of more rain on weekends
,⩥ class example: real vs artificial vanilla in chocolate chip cookies.Ans:
- Phelan baked batches of cookies with real vanilla and with artificial
vanilla
- asked wife which one tasted better
- concluded that there was no difference in taste between the types of
vanilla used
⩥ class example: is maze running genetic in mice? Ans: - have "maze
dull" and "maze bright" mice
- with each generation, test all mice for maze learning ability and breed
only the top 20% and bottom 20%
- observe new generations
- conclusion: over time, the extremes got more and more exaggerated
- maze running is not genetic but the allele for fear is in mice; less fear =
solve maze quicker, more fear = solve maze slower
⩥ how to increase experiment's power.Ans: - randomize subjects
- control your study
- use a double-blind design
R.C.D. - rat's cause diseases
⩥ what is the cost-benefit analysis of having a more controlled
experiment? Ans: it's a poorer model of the situation of interest
, ⩥ 2. How does a hypothesis differ from a theory or prediction? Ans: - a
prediction only offers a guess of what will happen in the future
- a theory is a widely accepted idea that has serious evidence behind it,
backing it up; ex: theory of evolution
- a hypothesis is a proposed explanation for observed phenomena
- a hypothesis must generate testable predictions
- theories are generally broader than hypotheses
⩥ null hypothesis.Ans: - a hypothesis that states a lack of relationship
between 2 factors
- easy to disprove
ex: Echinacea has NO effect on the likelihood of catching the common
cold or the duration of the symptoms of a cold
⩥ is it possible to prove a hypothesis is absolutely and permanently true?
Ans: no it's impossible
⩥ 3. What does it mean to control an experiment? Ans: - make sure there
are no underlying differenced between the experimental groups
- change only ONE variable at a time
- treat all subject the same except for the one deviation which would not
get the treatment and be the control group
2026 QUESTIONS WITH ANSWERS FULL
SOLUTION.
⩥ what does a "critical experiment" do.Ans: put a hypothesis to the test,
the results can decisively determine whether a hypothesis is correct
⩥ class examples of scientific method.Ans: - does it rain more on
weekends?
- real vs artificial vanilla
- "maze bright" vs "maze dull" rats
⩥ class example: does it rain more on weekends? Ans: - find average
Monday and Saturday rainfall; rains 22% more on Saturdays
- hypothesis: particular matter from car exhaust builds up during the
week leading to cloud formation and then rain on the weekends
- experiment: collect data from somewhere with no cars (ocean)
- results: there is equal rainfall on each day in the ocean, PROVING that
car exhaust affects the trend of more rain on weekends
,⩥ class example: real vs artificial vanilla in chocolate chip cookies.Ans:
- Phelan baked batches of cookies with real vanilla and with artificial
vanilla
- asked wife which one tasted better
- concluded that there was no difference in taste between the types of
vanilla used
⩥ class example: is maze running genetic in mice? Ans: - have "maze
dull" and "maze bright" mice
- with each generation, test all mice for maze learning ability and breed
only the top 20% and bottom 20%
- observe new generations
- conclusion: over time, the extremes got more and more exaggerated
- maze running is not genetic but the allele for fear is in mice; less fear =
solve maze quicker, more fear = solve maze slower
⩥ how to increase experiment's power.Ans: - randomize subjects
- control your study
- use a double-blind design
R.C.D. - rat's cause diseases
⩥ what is the cost-benefit analysis of having a more controlled
experiment? Ans: it's a poorer model of the situation of interest
, ⩥ 2. How does a hypothesis differ from a theory or prediction? Ans: - a
prediction only offers a guess of what will happen in the future
- a theory is a widely accepted idea that has serious evidence behind it,
backing it up; ex: theory of evolution
- a hypothesis is a proposed explanation for observed phenomena
- a hypothesis must generate testable predictions
- theories are generally broader than hypotheses
⩥ null hypothesis.Ans: - a hypothesis that states a lack of relationship
between 2 factors
- easy to disprove
ex: Echinacea has NO effect on the likelihood of catching the common
cold or the duration of the symptoms of a cold
⩥ is it possible to prove a hypothesis is absolutely and permanently true?
Ans: no it's impossible
⩥ 3. What does it mean to control an experiment? Ans: - make sure there
are no underlying differenced between the experimental groups
- change only ONE variable at a time
- treat all subject the same except for the one deviation which would not
get the treatment and be the control group
