chemistry

• Statistics


  A branch of applied Mathematics that deals with the collection, organization, presentation, analysis and interpretation of data in order to provide meaningful information to the people or organizations that will use these data
• Categories of Statistics


  • Inferential Statistics - generalizing from samples to populations, performing hypothesis testing, determining relationships among variables, and making predictions
  • Descriptive Statistics - collecting and organizing of data
• Variable


  A characteristic that takes two or more values which varies across individuals
• Descriptive Analysis


  Analyzes population, and parameter
• Inferential Analysis


  Analyzes sample, &
• Measures of Central Tendency

  • Mean - the total sum of values in a sample divided by the number of values in your sample (average)
  • Median - middle number
  • Mode - most frequently occurring value
• Measures of Variability

  • Range - difference between the largest and smallest value in the data set
  • Standard Deviation - measures the extent of scattering in a set of values, typically compared to the mean value of the set
  • Variance - a measure of how data points differ from the mean
• Types of Inferential Tests

  • Tests of group differences - determine whether two populations differ with respect to their mean scores on some response variable
  • Tests of associations (relationship) - there is a single population of individuals, and you want to know whether there is a relationship between two or more variables within this population
• Parametric Test


  • Require normal distribution, the level of measurements of which are expressed in an interval or ratio data
  • The sample must be representative of the target population so that the variables being measured fall within the normal distribution for that population
  • The subjects in the two groups being examined need to be either randomly assigned to each group or each group must be matched according to the respondents' age, sex, etc
• Kinds of Parametric Tests

  • Numerical Data
  • Normal Distribution
  • Number of Samples
• Non-Parametric Test


  • Do not require a normal distribution and utilizes both nominal and ordinal data
  • The sample is not considered representative of the population and the variables selected are probably not normally distributed
• Parametric Test vs Non-Parametric Equivalent

  • Paired T-Test vs Wilcoxon Rank Sum Test
  • Unpaired T-Test vs Mann-Whitney U Test
  • Pearson Correlation vs Spearman Correlation
  • One Way Analysis of Variance vs Kruskal Wallis Test
• Bell Curve

  Called the Normal Distribution or Gaussian Distribution. Mean=Median=Mode, Symmetric
• Hypothesis Testing


  An objective method of making decisions or inferences from sample data (evidence). The process of making an inference or generalization on population parameters based on the results of the study on samples
• Null Hypothesis (H0)


  An assertion we hold as true unless we have sufficient statistical evidence to conclude otherwise. No Significant Difference
• Alternative Hypothesis (Ha)


  The negation of the null hypothesis
• Significance Level


  The probability of rejecting the null hypothesis when it is true, also known as the type I error. Normally set at 5% which means that there is a 1 in 20 chance of rejecting the null when it is true
• Types of Error


  • Type I Error - Rejecting the null hypothesis when it is true
  • Type II Error - Failing to reject the null hypothesis when it is false
• Test Statistic


  A value calculated from a sample to decide whether to reject or not the null hypothesis (H0) and varies between tests
• Decision Rule


  • P value approach: If the computed test value is less than the p value, reject the Null hypothesis
  • Critical Value Approach: If the computed test value is greater than the critical value, reject the Null hypothesis
• Dependent T-Test in MS Excel


  1. Dependent t-test or Paired Test is used to determine if there is a significant difference between two sets or groups of related or correlated observations for small sample size, n≤30 and population variance is unknown

  2. Paired Two Sample For Means is used when your sample observations are naturally paired
• 1. TEST

  Used to determine if there is a significant difference between two independent or different groups in terms of their means with known variance. It is used to compare the two-sample means taken from the same population when the samples are equal to or greater than 30
• 1. F TEST
  2. statistic is the ratio of two variances, or technically, two mean squares. The F-Test Two-Sample for Variances tool tests the null hypothesis that two samples come from two independent populations having the equal variances
• ANOVA


  • One-way analysis of variance – used to test when there is only one variable
  • Two-way analysis of variance – used to test when two variables are involved; the column and the row variables. Used also in determining the interaction effect between the variables
• Pearson Product Moment Coefficient of Correlation (r)

  • Pearson's correlation may ALWAYS be used to test an associative research hypothesis as long as the variables being analyzed are both quantitative
  • The value of the correlation coefficient varies between +1 and -1. A value of ± 1 indicates a perfect degree of association between the two variables
• Degree of Correlation


  As the correlation coefficient value goes towards 0, the relationship between the two variables will be weaker. The direction of the relationship is indicated by the sign of the coefficient; a + sign indicates a positive relationship and a – sign indicates a negative relationship
• Medicine


  Substances used to treat, prevent, or manage diseases, illnesses, and conditions in humans and animals. They work by interacting with the body's systems to produce therapeutic effects
• Types of Medicine


  • Prescription Medicines - Require a doctor's prescription for use
  • Over-the-Counter (OTC) - Can be purchased without a prescription
  • Generic Medicines - Have the same active ingredients, dosage forms, and effects as brand-name drugs but are typically sold at lower prices
  • Herbal and Dietary Supplements - Products derived from plants or other natural sources, used to promote health and wellness. They are not strictly regulated like pharmaceutical drugs
• Generic, Brand, and Chemical Names of Medicine

  Every medicine has 2 names: a brand name, from the pharmaceutical company that makes it, and a generic name, which is the active ingredient
• Brand Name

  Name from the pharmaceutical company that markets the medicine
• Generic Name


  Medicine's active ingredient that makes it work
• Chemical Name


  Scientific name based on the compound's chemical structure, almost never used to identify the drug
• Mechanism of Actions


  1. Target specific receptors, enzymes, or other molecular structures

  2. Act as agonists, mimicking natural substances

  3. Act as antagonists, blocking the action of certain molecules
• Pharmacokinetics


  1. Absorption

  2. Distribution

  3. Metabolism

  4. Excretion
• Forms of Administration


  • Orally
  • Topically
  • Through injection
• Food and Drug Administration

  Regulatory agency mandated to ensure the safety, efficacy or quality of health products
• Homeopathy


  A form of alternative medicine based on the principle of "like cures like"
• Homeopathic Preparations


  Prepared using a small amount of a natural substance diluted in water or alcohol, then further diluted and succussed
• Safety of Homeopathy


  Generally considered safe due to high levels of dilution, but should still be approached with caution
• Cancer


  A group of diseases characterized by the uncontrolled growth and spread of abnormal cells in the body