In science, to make a conclusion you compare your hypothesis to your experimental results.
There are various ways to state the steps of the scientific method. They look generally like this:
1. Make an observation or ask a question.
2. After researching, state the problem.
3. Form a hypothesis.
4. Develop an experiment to test the hypothesis.
5. Gather data -- conduct the experiment.
6. Reach a conclusion by comparing the hypothesis to the evidence/experimental results.
7. Verify the results and communicate the results.
Depending on the text, there are steps involving analyzing the data, etc... You will want to look in the text you are using (lecture notes, etc...) to get the exact phraseology.
You should compare your results and data with your original hypothesis. Remember, it's okay to have a hypothesis that was shown to be false. That's science. You didn't mess up. In that case, you basically conclude that what you originally thought, was false, and now you have the data to back that up. Too often my students try too hard to hypothesize the exact right answer. That's not a good way to do science. Your conclusion is what your teacher is going to look at for "the right answer."
According to the scientific method, in your conclusion you will compare your hypothesis (your prediction/educated guess) to the actual result. Either your hypothesis will have been correct and you will use your data to back it up, or your hypothesis will be incorrect and you compare it to the actual results, using your data as well as showing mistakes you may have made.
To form a scientific conclusion in a lab report, you compare your hypothesis with your experimental results. Your hypothesis is your educated guess per say, on what you believe the experiment will show or prove. Your data can either support or contradict that. This is what you discuss in your conclusion, whether or not the data supported your hypothesis and why or why not.
In a scientific experiment, when you make a conclusion, you compare your hypothesis to your results. Your hypothesis is what you guessed would happen, and it is based off of the information you have researched or gathered. The results are what actually occurred in the experiment, which is usually collected through observations and/or numerical data.
In your conclusion, you should always compare your results to what you hypothesized. Before you even began the lab, you should have predicted what you believed would occur when you manipulated a certain variable. If the results differed from your hypothesis, you would need to review potential errors and how those errors may have impacted your final results.
In a conclusion, you would compare your hypothesis to your actual results and how they are the same or how they were different.