# Introduction to Scientific Method

## BIO 103 Introduction to Scientific Method and Graphing Activity

35 points

Due by 11:59 on due date noted on syllabus and D2L

**Purpose**

· Formulate null and alternative hypotheses

· Determine the appropriate type of graph to be used for different types of data sets

· Graph data

· Make a conclusion concerning the hypotheses

### Background

As discussed in chapter 1 in the textbook, scientific disciplines use the scientific method. Hypothesis formation is part of the scientific method. Graphing is also an important component for the presentation of scientific data.

### Assignment

· Read the following scenario.

· Then write null and alternative hypotheses comparing the number of flying insects observed on the three different data collection days as a function of temperature. (You may need to research what a ‘null’ and ‘alternative’ hypothesis are and how they are written or see my example that is uploaded by this document.)

· Make a graph comparing the number of flying insects observed on the five different data collection days, as a function of temperature. Graph paper is provided at the end of this packet.

· Make conclusions based on your hypotheses and what you found.

### Scenario

An entomologist was curious if temperature affected the number of individuals of flying insects that could be observed. After all, insects are ectotherms. The entomologist collected data for a period of 3 hours on each of five different days. The average temperature for the 3-hour data collection window on the first day was 22°C. On this day, the researcher recorded 11 flying insects. On the second day of data collection, the average temperature during the 3-hour data collection period was 28 °C. On this day, the entomologist observed a total of 36 flying insects. On day 3, the temperature was 26 °C and 29 flying insects were observed. On day 4, the average temperature was 23 °C and 15 flying insects were observed. On day 5, the average temperature was 25 °C and 22 flying insects were observed.

### Hypothesis Formation

· A null hypothesis (Ho) is written in a “negative form”. It basically states that there is no difference in the measured result between the groups being tested. The alternate option to the null hypothesis is an alternative hypothesis. An alternative hypothesis (HA) is basically the opposite of the null hypothesis and therefore states that there is a difference in the measurable result between the groups being compared.** **Remember to include an explanation in your alternative hypothesis, and how you would measure the outcome.

· Statistical analyses are typically used to determine if the null hypothesis will be rejected or accepted.

· Write a clear null hypothesis and alternative hypothesis addressing the possible relationship between the number of flying insects observed for the two data collection days as a function of temperature.

**HO**:

**HA**:

· Does the data suggest that the null hypothesis is accepted or rejected? (You do not have to run a statistical analysis.)

### Graphing

The type of graph used to present data depends on the type of data depicted on the graph.

After reading the following information about different types of graphs, make a graph for the data provided in this assignment scenario comparing the number of flying insects observed each day.

· Pie charts are used to illustrate the percentages of the total number of measurements that fall into specific categories. They are often used to contrast the percentage of measurements in each category relative to 100%.

· Bar graphs are used to show data measurements for descriptive (qualitative) categories. The bars on the graph are separated by a space between each bar.

· Histograms are similar to bar graphs. However, histograms show quantitative data represented as numerical intervals on the x-axis rather than descriptive categories on the x-axis. The bars representing the plotted data are not separated.

· Line graphs are used to show continuous, quantitative data. For example, data that are recorded continuously over a period of time.