Temperature and sampling parameters in Prompt Engineering / GenAI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the 'temperature' parameter control in text generation models?

Temperature controls how random or creative the model's output is. A low temperature (close to 0) makes the output more predictable and focused, while a high temperature (above 1) makes it more random and diverse.

beginner

Explain 'top-k sampling' in simple terms.

Top-k sampling means the model only picks the next word from the top 'k' most likely words. This limits choices to the best options and helps keep the output sensible.

intermediate

How does 'top-p' (nucleus) sampling differ from 'top-k' sampling?

Top-p sampling picks words from the smallest group whose combined probability is at least 'p' (like 0.9). This group size can change, unlike top-k which always picks a fixed number of words.

beginner

What happens if you set temperature to 0 in a language model?

Setting temperature to 0 makes the model always pick the most likely next word, making the output very predictable and repetitive.

beginner

Why might you want to use a higher temperature when generating creative text?

A higher temperature adds randomness, which can make the text more creative and surprising, useful for stories or poems.

What does increasing the temperature parameter do to the model's output?

A Limits output to top 1 word only

B Makes output more predictable and repetitive

C Makes output more random and diverse

D Stops the model from generating text

Increasing temperature increases randomness, making output more diverse.

In top-k sampling, what does 'k' represent?

A The number of top probable words to choose from

B The probability threshold for word selection

C The temperature value

D The length of the generated text

Top-k sampling picks the next word from the top 'k' most likely words.

Which sampling method adapts the number of candidate words based on cumulative probability?

A Top-p (nucleus) sampling

B Top-k sampling

C Greedy sampling

D Beam search

Top-p sampling selects words from the smallest set whose total probability exceeds 'p'.

What is the effect of setting temperature to 0?

A Model picks words randomly

B Model always picks the most likely next word

C Model stops generating text

D Model picks words from top 10 only

Temperature 0 means deterministic output by always choosing the highest probability word.

Why use sampling methods like top-k or top-p instead of always picking the most likely word?

A To make the output shorter

B To avoid generating any text

C To reduce computation time

D To add variety and creativity to the generated text

Sampling adds randomness, making text more interesting and less repetitive.

Describe how temperature affects the randomness of text generated by a language model.

Think about how predictable or surprising the text feels.

Explain the difference between top-k and top-p sampling in simple terms.

Consider how many words the model can choose from next.

Practice

1. What does the temperature parameter control in AI text generation?

easy

A. The speed of the AI's response

B. The length of the generated text

C. How random or focused the AI's answers are

D. The number of words the AI can use

Solution

1. Step 1: Understand the role of temperature

   The temperature parameter adjusts randomness in AI output. A low temperature makes answers more focused and predictable, while a high temperature increases randomness and creativity.

2. Step 2: Match the description to the options

   Only How random or focused the AI's answers are correctly describes temperature as controlling randomness or focus in AI answers.

3. Final Answer:

   How random or focused the AI's answers are -> Option C

4. Quick Check:

   Temperature controls randomness = A [OK]

Hint: Temperature means randomness level in AI output [OK]

Common Mistakes:

• Confusing temperature with output length
• Thinking temperature controls speed
• Mixing temperature with vocabulary size

2. Which of the following is the correct way to set the temperature to 0.7 in a Python API call for text generation?

easy

A. generate_text(temperature=0.7)

B. generate_text(temp=7)

C. generate_text(temperature='0.7')

D. generate_text(temperature=7)

Solution

1. Step 1: Identify correct parameter name and type

   The parameter controlling randomness is named temperature and expects a float value between 0 and 1 (commonly).

2. Step 2: Check each option

   generate_text(temperature=0.7) uses the correct parameter name and a valid float value 0.7. generate_text(temp=7) uses wrong parameter name and integer 7. generate_text(temperature='0.7') passes a string instead of float. generate_text(temperature=7) uses an invalid integer 7 instead of a float between 0 and 1.

3. Final Answer:

   generate_text(temperature=0.7) -> Option A

4. Quick Check:

   Correct parameter and float value = D [OK]

Hint: Use parameter name 'temperature' with float value [OK]

Common Mistakes:

• Using wrong parameter name like 'temp'
• Passing temperature as string instead of float
• Using values outside 0-1 range

3. Given this code snippet:

response = generate_text(prompt='Hello', temperature=0.1, top_p=0.9)
print(response)

What is the expected behavior of the AI output?

medium

A. Highly random and creative text

B. Very focused and predictable text

C. Text with many rare words

D. Text ignoring the prompt

Solution

1. Step 1: Analyze temperature value

   A temperature of 0.1 is very low, so the AI output will be focused and predictable, avoiding randomness.

2. Step 2: Analyze top_p value

   Top-p of 0.9 means the AI considers the most probable words covering 90% probability, further limiting randomness.

3. Final Answer:

   Very focused and predictable text -> Option B

4. Quick Check:

   Low temperature + top_p = focused output [OK]

Hint: Low temperature means focused output, not random [OK]

Common Mistakes:

• Assuming low temperature means more creativity
• Ignoring top_p effect on word choice
• Thinking AI ignores prompt with low temperature

4. You set temperature=1.5 in your AI call but get an error. What is the likely cause and fix?

medium

A. Temperature must be an integer; set it to 1

B. Temperature must be a string; set it to '1.5'

C. Temperature cannot be set; remove it

D. Temperature must be between 0 and 1; set it to 0.9

Solution

1. Step 1: Understand valid temperature range

   Temperature values are usually required to be between 0 and 1 to control randomness properly.

2. Step 2: Identify error cause and fix

   Setting temperature to 1.5 is outside the valid range, causing an error. Fix is to set it to a valid value like 0.9.

3. Final Answer:

   Temperature must be between 0 and 1; set it to 0.9 -> Option D

4. Quick Check:

   Temperature range 0-1 = B [OK]

Hint: Temperature must be 0 to 1, not above [OK]

Common Mistakes:

• Using values above 1 for temperature
• Thinking temperature must be integer
• Passing temperature as string

5. You want the AI to generate creative but coherent stories. Which combination of temperature and top_p is best?

hard

A. temperature=0.8, top_p=0.9

B. temperature=0.2, top_p=0.5

C. temperature=1.0, top_p=0.1

D. temperature=0.0, top_p=1.0

Solution

1. Step 1: Understand desired output style

   Creative but coherent stories need some randomness (creativity) but also focus (coherence).

2. Step 2: Evaluate each parameter combination

   temperature=0.8, top_p=0.9 has temperature 0.8 (moderately high randomness) and top_p 0.9 (limits to likely words), balancing creativity and coherence. temperature=0.2, top_p=0.5 is too low randomness, temperature=1.0, top_p=0.1 has very low top_p causing incoherence, temperature=0.0, top_p=1.0 is zero randomness, so very dull.

3. Final Answer:

   temperature=0.8, top_p=0.9 -> Option A

4. Quick Check:

   Moderate temperature + high top_p = creative & coherent [OK]

Hint: Use moderate temperature and high top_p for creative coherence [OK]

Common Mistakes:

• Choosing zero temperature for creativity
• Using very low top_p causing odd word choices
• Setting temperature too high causing nonsense