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Trying to keep track of your recipes? Here’s a handy trick to keep things in order with a paper database.

You will need

• A spiral bound notebook – if you can get one with thick paper, like a visual diary, this activity will be easier
• Skewers
• A pair of scissors
• Pens

Make the database

1. Bend the wire on the notebook so you can get the pages out without tearing them. Once you have the pages out, set aside the front and back cover, and the wire – you won’t need them.

   

2. On each page, write the recipe for a food you might serve at a party. Keep going until you can’t think of any more types of food.
3. Take the first recipe. Next to each of the holes, write the name of one of your friends.
4. Read each name down the side of the page. If the person named likes the food on the recipe, cut away the little bit of paper separating the hole from the edge of the sheet.
5. When you’ve finished, take the next recipe. Label the holes down the side with exactly the same names on the same holes.
6. On the new recipe, cut out the holes next to the name of each person who likes it.
7. Keep labelling the holes and cutting them for every recipe that you wrote down.

   

Use the database

1. Work out who’s coming to your party.
2. Get all of your recipes together and put them in a neat pile so all the holes line up.
3. For each person coming to the party, stick a skewer into the hole labelled with their name.
4. Keeping the skewers in the holes, lift up the skewers so the recipes are hanging from the skewers.
5. Any recipes that hang aren’t liked by someone coming to the party. Recipes that fall to the ground are liked by everyone, which makes it easy to work out what to cook.

   

What’s happening?

This activity is all about doing lots of things at the same time. If you put one skewer through a hole in one recipe, it will fall off if you’ve cut that hole. If the hole isn’t cut, the recipe will stay on the skewer. When you stick a skewer through all the recipes, you’re doing the same thing, only with every recipe at the same time. If you use more than one skewer, then you’re checking several holes in every recipe at the same time. Each recipe will only fall if every skewered hole is cut.

If you only have a few recipes, this might seem like a very complicated way of sorting through them, and you might find it quicker just to look through all your recipes. However, if you have hundreds of recipes, it could take a long time to sort through all of them individually. This method can sort through all of them very quickly.

This system of cards with holes in them is over 60 years old. Commonly known as ‘Cope-Chat’ or ‘McBee Keysort’ cards, they were used for a wide range of applications, from medical studies to library catalogues. Users developed many impressive techniques to search for information. For example, a lot of cards would have two holes for each property – one where you cut it if it is true, and one where you cut if it is false. That way, you can search for a food that is liked by George, and disliked by Peter.

Applications

Card indexes like this have now been replaced with computer databases. These databases are actually quite similar to the card index you made in this activity. They contain a series of records, which are like the cards in this activity. The holes are called ‘fields’ and they are a bit more complicated than in the activity. Fields can be tick boxes or numbers or even words, and they can be searched. One of the main advantages of computer databases is that they can keep thousands or millions of records, and each can have as many searchable fields as you need.

Databases are a very good way to organise information, because you can find things using just a few quick questions. For example, internet search engines keep databases about what information is on websites. When you type something into a search engine, it looks up the database to find the best matches to your request. This way, they can search the entire internet, without having to ‘read’ every website every time someone does a search.

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