1. Making a Dichotomous Key

2. Making a Dichotomous Key
In order to classify things, consider your original grouping:
Tea Popcorn Lemonade
Cheese Coffee Rice
Fanta Yogurt Milk

3. Making a Dichotomous Key
Try to group them into 2 groups (remember, di = 2!)
Tea
Lemonade
Coffee
Fanta
Milk
Popcorn
Cheese
Rice
Yogurt

4. Making a Dichotomous Key
You’ve created your first dichotomy!
Common Foods & Drinks
Tea
Lemonade
Coffee
Fanta
Milk
Popcorn
Cheese
Rice
Yogurt

5. Making a Dichotomous Key
Now keep dividing into two groups, each time…
Common Foods & Drinks
Consumed Cold:
Lemonade
Fanta
Milk
Consumed Warm:
Tea
Coffee
Grains:
Popcorn
Rice
Dairy:
Cheese
Yogurt

6. Making a Dichotomous Key
…keep going, creating more dichotomies…
Common Foods & Drinks
Consumed Cold:
Lemonade
Fanta
Milk
Consumed Warm:
Tea
Coffee
Grains:
Popcorn
Rice
Dairy:
Cheese
Yogurt
Generally savoury:
Cheese
Citrus:
Lemonade
Fanta
Often sweet:
Yogurt
Non-Citrus:
Milk
lemon?
Tea
No lemon?
Coffee
“popped”
Popcorn
steamed
Rice

7. Making a Dichotomous Key
… until each item is in its own distinct category. Voila!
Common Foods & Drinks
Consumed Cold:
Lemonade
Fanta
Milk
Consumed Warm:
Tea
Coffee
Grains:
Popcorn
Rice
Dairy:
Cheese
Yogurt
Generally savoury:
Cheese
Citrus:
Lemonade
Fanta
Often sweet:
Yogurt
Non-Citrus:
Milk
lemon?
Tea
No lemon?
Coffee
“popped”
Popcorn
steamed
Rice
Carbonated:
Fanta
Not carbonated:
Lemonade

8. Making a Dichotomous Key
You know you’ve done it right if you can read it backwards and get a description of the item:
Yogurt is an often sweet dairy food!
Common Foods & Drinks
Consumed Cold:
Lemonade
Fanta
Milk
Consumed Warm:
Tea
Coffee
Grains:
Popcorn
Rice
Dairy:
Cheese
Yogurt
Generally savoury:
Cheese
Citrus:
Lemonade
Fanta
Often sweet:
Yogurt
Non-Citrus:
Milk
lemon?
Tea
No lemon?
Coffee
“popped”
Popcorn
steamed
Rice
Fanta is a carbonated citrus cold drink!
Carbonated:
Fanta
Not carbonated:
Lemonade

9. Now, try it!
Create a dichotomous key of Coins:

10. Try it again!
Let’s sort these Ungulates!

11. One more!
Spicy, spicy peppers! Classify ‘em!

12. Other formats:
This type of ‘checklist’ key is often found in field guides since it is more compact

13. Now you know! And…