Advanced Higher Biology Unit 3 Investigative Biology

3 Critical evaluation of biological research (a) Evaluating background information.

SQA

Success criteria  Explain what a title should possess in a scientific report in terms of the dependent and independent variable.  Explain what the abstract defines.  Explain the operationalisation of variables.  Explain the effect of having a hypothesis in your introduction.  Explain which variables should be defined in your method.

Research Article Plos  ction?uri=info:doi/ /journal.pone &representation=PDF ction?uri=info:doi/ /journal.pone &representation=PDF

The title Should provide a succinct explanation of the investigation: ­ What was the independent variable altered? ­ What was the dependent variable measured? ­ Which organism/system/molecule was studied?

Imprecise and uninformative titles  Dopa oxidase investigation…  Investigating the effect of caffeine on behaviour!  Woodlice and humidity…  An investigation into how light affects plants.  Humans and exercise… Brilliant!

A template for a precise title An investigation into the effect of changing [independent variable] on [dependent variable] in [the study organism/system/molecule]

Research Article - Title

Abstract The abstract (or summary) outlines the aims and results of the study: ­ Which variable was altered and how? ­ Which variable was measured and how? ­ What was the effect of altering the independent variable on the dependent variable?

Abstract

Introduction: general presentation Short sentences should be used to improve the clarity of the writing. Terms that are unfamiliar to the intended readers should be defined. Statements made should be supported by appropriate references.

Introduction  The aims and hypotheses of the investigation must be included at the beginning.  Must include information to explain the rationale of the study and place it in the wider context of existing understanding (including conflicting positions).  Decisions regarding the basic selection of study methods and organisms should be stated.  Several sources should be selected to support statements and referenced in a standard form, e.g. the Harvard system.

Aim  Should follow directly from the title of the investigation: The aim of the investigation was to measure the effect of changing [independent variable] on [dependent variable] in [the study organism/system/ molecule].

Introduction

‘Operationalisation’ of the variables  The independent and dependent variables (and important confounding variables) should be fully defined.  temperature  temperature of water bath  woodlice movement  total distance travelled by woodlice over muslin sheet in 30 seconds

Introduction: hypothesis  A prediction for the outcome of the investigation if a certain theory were true.  The hypothesis is the statement that the investigation is designed to test. The value of [dependent variable] is expected to [increase/decrease] when the value of [independent variable] [the study organism/system/molecule] is [increased/decreased].

Method  The independent and dependent variables should be ‘operationalised’ (precisely defined).  The information must be detailed enough to allow another investigator to replicate the work.

Method: details to check for  How the independent variable was altered and how many values were used.  How the dependent variable was measured.  How the confounding variables were controlled.  Description of any controls that were included.  Sample size – number of individuals in study.  Number of repeats and/or replicates carried out.

Method: details to check for  Volumes and concentrations of solutions used.  Temperature and pH of solutions.  Timing/duration of manipulations.  Settings for specialist items of equipment used.  Source of any chemicals/tissues/ organisms used.  Age/mass/sex of individuals used.

Success criteria  Explain what a title should possess in a scientific report in terms of the dependent and independent variable.  Explain what the abstract defines.  Explain the operationalisation of variables.  Explain the effect of having a hypothesis in your introduction.  Explain which variables should be defined in your method.