Observations, Predictions, and Inferences

See, hear, smell, touch, and taste. They are the things scientists often do throughout the day. The first thing nearly every scientist learns how to do is make good observations. Observations are the things people notice about the world using the five senses. There are many kinds of observations, but there are two main types.

Quality observations answer questions such as: How does it feel? What does it smell like? What does it sound like? What is its color? Is it a solid? Is it liquid? Is it a gas? What does it taste like? Using jelly beans as an example, quality observations may include the following: Jelly beans are usually smooth. They may smell like fruit. They are solid and have different colors. Most of them are sweet.

On the other hand, quantity observations answer the questions such as: How many? How big? What is its size? How long is it? How tall is it? How thick is it? What is its temperature? How fast can it move? What is the volume? How much is there? Using jelly beans again as an example, quantity observations may include the following: A bag of jelly beans may have 20 or 100. Jelly beans are small, maybe an inch. They are room temperature. One may weigh a half an ounce.

There are many other questions for each observation and not every question is answered by a scientist when doing an experiment. Quality observation answers may include: smooth, rough, slippery, red, blue, invisible, liquid, and many others. Quantity observation answers may include 6 inches, 72°F, 3 pounds, 8 feet by 4 feet, 16 ounces, 2 liters, and more. For quantity observations, a ruler, thermometer, scale, or another measuring tool may be used. When observing, it is also important to see things from different angles or distances, and for a short or long time-period.

Finally, once an observation is made, it must be recorded or written down on paper or in a journal. In addition, a scientist may record sounds, draw pictures, take photos, or make videos. It is important the observations are neat and organized. Why? Because other scientists may read and use each other's observations.

Once observations are made, they can be used to make predictions or inferences. Predictions are guesses, but not wild guesses. Predictions use the observations to learn what might happen in the future. On the other hand, an inference also uses observations, along with evidence and reasoning, to learn what might have happened in the past or in the present.

An example of a prediction is when a weather forecaster observes wind speed and direction to help predict temperature. They may also predict rain is coming when they see clouds. An example of an inference may include a person stepping outside and seeing puddles on the sidewalk. They make an inference: It must have rained. The observance of puddles in the past helps the person make the inference. The cause, rain, already occurred, which is different than a prediction of rain, which has yet to happen.

Sometimes people get observations, predictions, and inferences mixed up. One thing is certain: Observations, predictions, and inferences are used together to help scientists figure out how things work in the world today, in the past, and in the future.