Lesson Notes By Weeks and Term v4 - SHS 3
RE SEARCH AND DESIGN IN BIOMEDICAL SCIENCE
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RE SEARCH AND DESIGN IN BIOMEDICAL SCIENCE
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Subject: Biomedical Science
Class: SHS 3
Term: 2nd Term
Week: 20
Grade code: 3.4.1.LI.2
Strand code: 4
Sub-strand code: 1
Content standard code: 3.4.1.CS.1
Indicator code: 3.4.1.LI.2
Theme: BIOMEDICAL INNOVATION
Subtheme: RE SEARCH AND DESIGN IN BIOMEDICAL SCIENCE
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This lesson introduces the fundamental principles of designing and analysing a scientific study in the context of human health. In Ghana, we face various health challenges, from infectious diseases like malaria to lifestyle diseases like hypertension. Understanding how to scientifically investigate a health question is the first step toward finding local solutions. This skill is not just for university researchers; it helps us to become critical thinkers who can evaluate health claims we see on social media or hear in our communities.
The foundation of all biomedical advancement is research. To conduct good research, we follow a structured process, often called the Scientific Method. Let's break down the key parts needed to design a study. A. From Observation to Research Question Everything starts with an observation. Observation: You notice that your classmates who drink "sobolo" (bissap) seem to have more energy in the afternoon than those who drink sugary sodas. Research Question: This observation leads to a question. A good research question is specific and testable. *Weak Question:* Is sobolo good for you? (Too broad) *Strong Question:* Does consuming 300ml of sobolo after lunch affect the academic concentration of SHS 3 students? (Specific, measurable, and testable) B. The Hypothesis: Your Testable Prediction A hypothesis is a clear, educated prediction about the outcome of your experiment. It's a statement, not a question. We often formulate two types: Null Hypothesis (H₀): This hypothesis states that there will be *no effect* or *no difference*. It's the "default" assumption we try to disprove. *Example:* Consuming 300ml of sobolo after lunch has no effect on the academic concentration of SHS 3 students. Alternative Hypothesis (H₁ or Hₐ): This hypothesis states that there *will be an effect* or a difference. This is usually what the researcher actually thinks will happen. *Example:* SHS 3 students who consume 300ml of sobolo after lunch will have higher academic concentration compared to those who do not. C. Variables: The Building Blocks of an Experiment Variables are any factors that can change or be changed in an experiment. Understanding them is crucial for a good design. Independent Variable (IV): This is the one factor that *you, the researcher, manipulate or change* to see its effect. It's the "cause". *In our sobolo study:* The IV is the consumption of sobolo (one group gets it, another doesn't). Dependent Variable (DV): This is the factor that you *measure* to see if the independent variable had an effect. It's the "effect" you are looking for. It *depends* on the independent variable. *In our sobolo study:* The DV is academic concentration. We could measure this using a short quiz, a puzzle, or a timed attention test. Controlled Variables (Constants): These are all the other factors that could possibly influence the dependent variable. You must keep them *the same (constant)* for all groups in your experiment to ensure a fair test. If you don't control them, you won't know if your IV was the true cause of the change. *In our sobolo study, controlled variables would include:* The time of day the test is taken. The difficulty of the concentration test. The age range of the students. The amount of sleep students had the night before (as much as possible). The lunch meal eaten by all participants. D. Experimental Design: The Blueprint of Your Study A good design ensures your results are reliable. It must include: Participants: Who are you studying? (e.g., 40 SHS 3 students from Accra High School). Groups: You need at least two groups for comparison. Experimental Group: This group receives the "treatment" or the independent variable you are testing (e.g., the group that drinks the 300ml of sobolo). Control Group: This group does *not* receive the treatment. They serve as a baseline for comparison (e.g., the group that drinks 300ml of water instead of sobolo). Using water ensures that the act of drinking itself is not causing the effect. Procedure: A step-by-step list of what you will do. It must be detailed enough for someone else to replicate your experiment exactly. *Example Procedure:* Recruit 40 volunteer SHS 3 students and obtain their consent. Randomly assign 20 students to Group A (Experimental) and 20 to Group B (Control). Ensure all 40 students eat the same lunch (e.g., jollof rice with chicken). At 1:00 PM, give Group A 300ml of sobolo. Give Group B 300ml of water. At 2:00 PM, administer a 15-minute concentration test (e.g., a "find the difference" puzzle) to all 40 students in the same quiet room. Collect and score the tests. The score is the measure of concentration. Data Collection and Analysis: How will you record and make sense of your results? Data Collection: Record the scores for each student in a table, separated by group. Data Analysis: A simple way to analyse is to calculate the mean (average) score for each group. Mean Score for Experimental Group = (Sum of scores in Group A) / 20 Mean Score for Control Group = (Sum of scores in Group B) / 20 Conclusion: Compare the means. If the average score of the sobolo group is significantly higher than the water group, your data supports the alternative hypothesis (H₁). If the scores are very similar, you cannot reject the null hypothesis (H₀). E. Ethical Considerations When studying humans, ethics are paramount. Informed Consent: Participants must understand the study and agree to take part without pressure. For minors, parental consent is also needed. Confidentiality: The identity and data of participants must be kept private. Do No Harm: The experiment should not cause any physical or psychological harm to the participants.
Guided Practice (With Solutions)
Instructions: Let's work through these examples together as a class.
Question 1: A researcher wants to test if a new mosquito repellent made from local neem ("dungonyaro") leaves is effective. She asks one group of 10 people to apply the neem repellent and another group of 10 people to apply a lotion with no repellent. After one hour in a mosquito-prone area, she counts the number of mosquito bites on each person. Identify the Independent Variable (IV), Dependent Variable (DV), and one important Controlled Variable.