There are dissimilar methods of reviewing politics other than comparative such as experimental, statistical and case study. All of them have their own advantages and disadvantage. Comparison is a popular research technique which has several benefits and widespread application.
Comparative approach are explained by numerous researchers as relating to a type of evaluation that contrasts one ideology or investigative plan aligned with others. It may have a possibility of being substituted by another one that can be used to explicate the same others that would explain the same common trend (Gerring 2008). Additionally, Keaty (2008) stated that the comparative approach is the key scientific process existing, that an individual can utilise to control theories and analyse the correlations of more than one variable, while maintaining all invariance that can latently alter factors.
Although comparative approach in political science is considered to be advantageous in linking theory to evidence, enhancing it as a scientific discipline, there are number of constraints that limit its possibilities and can impair its usefulness (Daniele Caramani, 2014).
Arend Lijphart claimed that "the phrase comparative politics specifies the "how" but does not postulate the "what" of the analysis". Comparativists usually compare and contrast different component parts of countries' political systems and try to discover differences and certain tendencies. Comparison entails following basic operations:
Compiling a list of things to compare,
Sorting and classifying them and, eventually,
Carrying out a basic act of comparison and making relevant conclusions.
Comparative method can be applied to compare political systems of different countries and also it can be used to compare political systems over time. There are different "schools" of the subject in the study of comparative politics as well institutionalism and functionalism. Institutionalism denotes to the practice of comparing political institutions such as governments, political parties. In has been documented that the main advantage of comparative method is that it makes the study of politics more structured and conclusions derived with this method are more precise. Despite of benefits, there are certain difficulties and drawbacks in comparative method as well.
Common problem of politics is that there are usually too many variables and too few cases. There are more than 200 countries in the world, but regrettably, they are all quite different. It is impossible to compare drastically different or completely identical countries, so in order to take the advantage of comparative method, only similar countries with minor differences should be compared and in some cases, it may prove to be complicated to find such.
It is appraised that the common classification of scientific methods by Arend Lijphart (1975) is comprehensible only to a limited extent and is in part ambiguous. He distinguishes between experimental and non-experimental methods. Among the non-experimental methods, which are applied in Comparative Politics in particular, he differentiates between the statistical and the comparative method as well as the case study. The difference between the statistical and the comparative method is challenging. Particularly, describing the statistical method as an independent procedure is haphazard.
The other problem raised by researchers with the comparative method is that research might be not objective and the researcher purposely chooses countries to demonstrate negative or positive moments to proof his/her opinion. For example, considering a proposition that countries with weak trade unions are more economically efficacious than countries with strong trade unions. Here, trade unionists and, on opposite side, managing directors have a political point to make, so more than likely their conclusions might completely diverge.
It is shown in political studies that in other subfields of political science, investigators may commonly work within definite general research programmes that offer clear base level assumptions to devise testable theories. But in comparative politics, analysts usually do not draw precise research programmes. Instead, they get theoretical inspiration in a wide range of general orientations-strategic choice models, state- centric approaches, patron-client models, theories of international dependency, and many more that emphasis certain major causal factors but that lack the all-encompassing generality that people normally associate with a Lakotosian research programme.
Comparative Politics tend to dangle normative evaluation of the world in favour of defining the political world and clarifying why it is the way it is. Nonetheless, it is important to recollect that comparativists do this not because they lack preferences or are unwilling to make normative judgments, but because as social scientists, they are committed first to offering systematic explanations for the world as it is. So they try to draw a realistic rather than normative model.
Comparative researchers may disagree about whether the assimilated knowledge , may help make the world a better place or help people to take better judgments about politics, but they usually accept that the job of defining and explaining is big enough. It can be cited through example, rather than evaluating whether democracy is good or not. Comparativists spend enough time to understand and identify the general conditions such as social, economic, ideological, institutional, and international under which democracies originally appear, become instability collapse into despotism and sometimes re-emerge as democracies. Additionally, sometimes in the Comparative Politics, it has been tried to draw parallel between two or more incomparable themes leading to imprecise conclusions. But the most bothersome weakness of comparative politics is the uncertainty of the area of study.
In Comparative Politics, several methods should be applied. However, methodical pluralism should only be accepted of under two conditions:
It is assessed that comparative approach has many limitations. Major concern is that researchers often have too many theories that fit the same data. This means that collecting valid and reliable data for the case researchers have selected to test theoretical relations can turn out to be formidable task. If this problem is insufficiently solved, it will undermine the quality of results (Daniele Caramani, 2014). Other disadvantages of comparative approach are that if inadequate data is available, it may be impossible to apply. Adjustments must be made as no two properties are ever identical. Precision of the method depends upon the appraiser's ability to recognize differences, and to make the proper adjustments for those differences.
To summarize, Comparative method is certainly the effective method to study and analyse contemporary politics, but researchers must be aware of the problems related with this process. Comparative method is used as a basis in all methods of valuation. Comparative method make simpler to a complex political reality and makes it more manageable. Comparative politics brings researchers into contact with political worlds other than political and cultural horizons. Comparative approach to studying of politics also enables researchers to move beyond mere description, toward explanation and within this method researchers can talk about comparative politics as a science. But negative side is that there is difficulty of operationalising variables. Any research of comparative method is susceptible to personal interests and motivations.