working scientifically

• The Scientific Method


  1. Scientists come up with hypotheses

  2. Scientists test hypotheses

  3. Several scientists will test a hypothesis

  4. If all the evidence supports a hypothesis, it's accepted - for now
• The Scientific Method


  • It's about how most scientists work, not how to 'do' science
• Hypothesis testing


  1. Scientists observe something they don't understand

  2. They come up with a hypothesis - a possible explanation

  3. They make a prediction based on the hypothesis and test it by gathering evidence

  4. If evidence backs up the prediction, they're a step closer to figuring out if the hypothesis is true
• Peer review


  1. Other scientists check results and scientific explanations to make sure they're 'scientific' before they're published

  2. It helps detect false claims, but doesn't mean findings are correct - just that they're not wrong in any obvious way
• If a scientist does an experiment that doesn't fit with the hypothesis

  The hypothesis may need to be modified or scrapped altogether
• Accepted hypotheses


  Often referred to as theories, they've been tested many times and survived
• Theories


  • They never become totally indisputable fact, if new evidence comes along that can't be explained using the existing theory, the hypothesising and testing starts again
• Types of models


  • Representational models
  • Computational models
• Models


  • They have limitations on what they can explain or predict
• The scientific method has been developed over time, and many people have helped to develop it
• Scientific developments can be great, but they can sometimes raise more questions than they answer
• Communicate scientific discoveries


  Scientists need to tell the world about their discoveries so people can make informed decisions
• Presenting scientific evidence


  • Reports in the media aren't peer-reviewed, so data can be presented in a biased way
  • People can present data in a biased way, even without knowing it
• Issues created by scientific developments


  • Economic issues
  • Personal issues
  • Social issues
  • Environmental issues
• Science can't answer every question, especially ethical ones
• New drugs that can boost 'brain power'


  Some people think they're good as they could improve concentration or memory, others say they're bad as they could give an unfair advantage in exams
• Hazard


  Something that could potentially cause harm
• Risk


  The chance that a hazard will cause harm
• Nothing is completely risk-free
• Estimating risk


  • You can estimate the size of a risk based on how many times something happens in a big sample over a given period
  • To make decisions about risky activities, you need to consider the chance of harm and the seriousness of the consequences
• People's perception of risk


  • People tend to view familiar activities as low-risk and unfamiliar activities as high-risk, even if that's not the case
  • People may over-estimate the risk of things with long-term or invisible effects
• Hazards from science experiments


  • Microorganisms
  • Chemicals
  • Fire
  • Electricity
• Part of planning an investigation is identifying and managing the hazards involved
• Perception of risk


  How risky people think something is
• People tend to view familiar activities as low-risk and unfamiliar activities as high-risk even if that's not the case
• Familiar activity perceived as low-risk


  • Cycling on roads
• Unfamiliar activity perceived as high-risk

  • Air travel
• People may over-estimate the risk of things with long-term or invisible effects, e.g. ionising radiation
• Hazards from science experiments


  • Microorganisms
  • Chemicals
  • Fire
  • Electricity
• Part of planning an investigation is making sure that it's safe
• Reducing risks from hazards

  1. Identify all hazards

  2. Think of ways to reduce risks
• Reducing risks


  • Wear gloves and safety goggles when working with sulfuric acid
  • Stand Bunsen burner on heat proof mat
• You can find out about potential hazards by looking in textbooks, doing some internet research, or asking your teacher
• Investigations are used to see if there are patterns or relationships between two variables
• Repeatable


  If the same person does an experiment again using the same methods and equipment, they'll get similar results
• Reproducible


  If someone else does the experiment, or a different method or piece of equipment is used, the results will still be similar
• If data is repeatable and reproducible, it's reliable and scientists are more likely to have confidence in it
• Valid results


  Repeatable, reproducible, and answer the original question
• Fair test


  Everything else that could affect the results should stay the same
• Independent variable


  The variable you CHANGE