膳荌砒秪赽睿坻聆講膳荌砒薯腔梓袧

扂蠅飲眭耋ㄛ悝氪飲醱還覂婓眭靡荎恅膳奻楷桶蹦恅腔揤薯﹝膳荌砒秪赽(IF)岆鼠腔算講膳壽蛁僅睿荌砒薯腔硌梓﹝秪森ㄛ竭嗣旃噶氪翋猁跦擂荌砒秪赽恁寁楷桶蹦恅腔膳﹝

荌砒秪赽腔數呾

荌砒秪赽珨啜岆跺掀硉﹝2010爛荌砒秪赽數呾鼠宒狟ㄩ²
IF_X = 2010爛垀竘蚚腔膳X衾2009爛睿2008爛楷桶腔垀衄蹦恅
膳X衾2009爛睿2008爛楷桶腔垀衄蹦恅

斕褫夔眒冪艘堤ㄛ2010爛腔荌砒秪赽硐夔婓2011爛摯眕綴妏蚚﹝膳荌砒秪赽藩爛數呾珨棒ㄛ甜鼠票婓抸伬繚芵楷桶腔膳竘蚚惆豢(JCR)笢﹝

荌砒秪赽腔妏蚚睿昫蚚

1. 釬峈算講膳壽蛁僅腔諦夤硌梓﹝.褫恁寁腔膳杅講操湮ㄛ膳腔荌砒秪赽枑鼎賸算講膳楷桶蹦恅淕极窐講腔諦夤硌梓﹝珨啜懂佽ㄛ荌砒秪赽硉埣詢ㄛ膳腔壽蛁僅埣湮﹝
2. 芞抎奩恁寁膳﹝.醴衄杅眕勀數腔膳堤唳昜﹝荌砒秪赽峈芞抎奩奪燴埜枑鼎賸珨笱瓚隅悵隱闡虳膳甜彶翹闡虳陔膳腔馱撿﹝
3. 悝扲嘛﹝.荌砒秪赽籵都掩蚚衾旃噶氪腔悝扲嘛徹最ㄛ筍岆ㄛ涴笱妏蚚源楊岆祥淏腔ㄛ秪峈荌砒秪赽躺桶尨膳腔淕极窐講ㄛ奧祥岆膳楷桶腔議蹦恅﹝
妏蚚荌砒秪赽奀腔蛁砩岈砐

妏蚚荌砒秪赽掀誕麼嘛膳奀ㄛ茼蛁砩眕狟岈砐ㄩ^4,5

1. 膳荌砒秪赽腔橈勤硉羶衄砩砱﹝瞰ㄩ荌砒秪赽峈2腔膳婓峚汜昜悝脹鍰郖壽蛁僅祥竭詢ㄛ筍婓漆栥悝鍰郖衄誕詢壽蛁僅﹝蚳珛膳 每 撞瓷濬膳麼壽蛁婐漲奪燴腔膳腔荌砒秪赽硉褫夔頗誕腴ㄛ秪峈膳蹦恅翋猁峈屾杅蚳珛黍氪堐黍麼竘蚚﹝⁶
   
   
2. 悝褪砃祥肮﹝祥肮旃噶鍰郖腔竘蚚炾嫦祥肮﹝秪森ㄛ荌砒秪赽祥夔蚚衾掀誕祥肮悝褪腔膳﹝瞰ㄩ瓟悝蹦恅腔竘蚚薹堈詢衾杅悝麼馱最濬蹦恅˙秪森ㄛ瓟悝膳腔荌砒秪赽詢衾杅悝摯馱最膳﹝⁷
   
   
3. 荌砒秪赽婓杻隅鍰郖砩砱祥湮﹝瞰ㄩ婓數呾儂褪悝鍰郖ㄛ頗祜蹦恅掩弝峈褪撮蹦恅腔翋猁倛宒﹝
   
   
4. 拸荌砒秪赽祥夔測桶膳祥笭猁﹝抸伬繚芵跦擂坻蠅腔竘恅杅擂踱數呾荌砒秪赽﹝杅擂踱彶賸埮25,000模肮俴机膳腔撓綱珨圉﹝杅擂踱腔葡裔毓峓煦票珩祥歙埱ㄛ議虳悝褪鍰郖膳腔彶翹薹猁詢衾坳鍰郖﹝鍚俋ㄛ呥抸伬繚芵杅擂踱彶翹賸懂赻60跺弊模腔膳ㄛ筍懂赻楷湛弊模腔膳甜祥嗣ㄛ奧硐衄屾杅準荎逄膳﹝
   
   

秪荌砒秪赽絳祡腔膳嫦瞰腔蜊曹

珨啜懂佽ㄛ荌砒秪赽勤膳晤憮迵勤旃噶氪肮脹笭猁﹝荌砒秪赽褫蚚衾算講膳腔珛憎ㄛ秪森竭嗣膳晤憮峈枑詢膳腔荌砒秪赽奧醱還覂揤薯﹝9鍚俋ㄛ荌砒秪赽珩褫眕紱諷﹝3,10-12瞰ㄩ擂楷珋ㄛ蹦恅梒腔竘蚚杅講郔湮ㄛ秪森膳褫鴃講嗣華楷桶机恅梒枑詢膳腔荌砒秪赽﹝膳晤憮褫眕蹦恅岆瘁眢掩竘蚚峈價插懂恁寁蹦恅﹝膳珩褫猁釬氪竘蚚膳腔坳蹦恅ㄗ傖峈※赻扂竘蚚§ㄘ﹝

荌砒秪赽腔杸測硌梓

荌砒秪赽梩翋絳華弇腔擁醱眒厥哿杅坋爛﹝筍岆ㄛ輪爛懂ㄛ蠅羲楷堤賸算講膳壽蛁僅腔杸測硌梓﹝擂楷珋ㄛ垀衄涴虳硌梓飲誑眈躇眈壽﹝珩憩岆佽ㄛ跦擂涴虳硌梓輛俴腔膳齬靡撓綱飲岆珨祡腔ㄛ呥膳腔橈勤齬靡湔婓船祑﹝秪森ㄛ婓恁寁壽蛁麼袧掘楷桶蹦恅腔膳奀ㄛ旃噶氪褫赻蚕華妏蚚眕狟睡珨笱硌梓ㄛ奧拸剒擁癹衾荌砒秪赽﹝^13-15 賦蹦
膳荌砒秪赽蚚衾嘛膳腔準都衄蚚腔馱撿ㄛ筍岆ㄛ妏蚚源楊斛剕磁燴﹝婓樵隅芘詨膳奀ㄛ祥夔硐統蕉荌砒秪赽﹝斛剕檣暮ㄛ壽蛁誕晜悝褪毓峓腔膳ㄗㄩ淖剿煦赽瓷燴悝ㄘ腔荌砒秪赽褫夔腴衾壽蛁悝褪毓峓嫘滓腔膳ㄗㄩ瓷燴悝娸祩ㄘ﹝郔綴ㄛ旃噶氪茼粒坳硌梓嘛膳窐講ㄛ等恅梒埭梓袧趙荌砒 睿杻涽秪赽煦硉ㄛ眕載疑華賸賤膳腔壽蛁僅睿荌砒薯﹝

Contributors

The impact factor and other measures of journal prestige

It is a well known fact that academics worldwide face pressure to publish in prestigious English language journals. And the journal impact factor (IF) is the most widely recognized indicator of journal prestige and influence. Accordingly, many people choose which journals to publish in based largely on the IF. ¹

Calculation of IF

The IF is basically a ratio. The 2010 IF is calculated as follows:²
IF_X = All citations in 2010 to articles published in Journal X in 2009 and 2008
All citable articles published in Journal X in 2009 and 2008

As you might have guessed, IFs for 2010 become available only in 2011 and so on. Journal IFs are calculated yearly and disclosed in the Journal Citation Reports (JCR) published by Thomson Reuters.

Use and misuse of the IF

1. As an objective measure of journal prestige. There are a vast number of journals to choose from, and the journals＊ IF provides an objective measure of the overall quality of work published in that journal. As a general rule, the higher the IF value of a journal, the more prestigious it is considered to be.
2. To select journals for libraries. There are tens of thousands of journal publications in existence. The IF provides library administrators with a tool to decide which journals to retain in their collections and which new ones to acquire for their libraries.
3. Academic evaluation. The IF is often used in the process of academic evaluations of researchers for tenure, grants, funding, etc. However, this use is incorrect because the IF is only meant to indicate the quality of an entire journal, not the quality of individual articles published in the journal.³
Beware while using the IF

When using the IF to compare or assess journals, be on the lookout for the following:^4,5

1. The absolute value of a journal＊s IF is meaningless. For example, a journal with an impact factor of 2 would not be very impressive in a subject like microbiology, but it would be in oceanography. Specialty journals - like disease-specific journals or journals focusing on disaster management - tend to have a low IF value because the journal articles are mostly read and cited by a small specialized audience.⁶
   
   
2. Disciplinary trends are different. Citation habits vary across different research areas. Therefore, IFs should not be used to compare journals across disciplines. For example, citation frequency is much higher in medicine than in mathematics or engineering; therefore, medical journals have higher IFs than mathematical and engineering journals.⁷
   
   
3. IFs are not very relevant in certain fields. For example, in computer science, conference proceedings are considered the principal form of scientific publication.
   
   
4. Not having an IF doesn＊t make a journal unworthy. Thomson Reuters calculates IFs based on their citation database. The database indexes roughly half of the approximately 25,000 peer-reviewed journals8 believed to be published. The coverage of their database is unevenly distributed as well, with some subject areas better indexed than others. In addition, although it indexes journals from 60 countries, there are not many publications from under-developed countries and only a small number of journals that publish in languages other than English.
   
   

Changes in journal practice because of the IF

The IF is as important, if not more, for journal editors as for researchers. The IF is used to measure journal performance, and many journal editors are under pressure to increase their journal＊s IF.⁹ Further, IFs can be manipulated.^3,10-12 For example, review articles have been found to attract the most number of citations, so journals may try to publish more review articles to increase their IF. Journal editors may select articles on the basis of how likely they are to be cited. Journals may also ask authors to cite other papers from the journal (called ※self-citations§).

Alternatives to the IF

The IF ruled the roost for several decades. However, alternative indicators of journal prestige have been developed in recent years. It has been found that all of these indicators correlate closely with each other. In other words, journal rankings based on these indicators tend to be similar, though there may be differences in the absolute journal rankings. So researchers should feel free to use any one of the below indicators, and not limit themselves to the IF, when selecting journals to follow or publish in.^13-15 Conclusion
The journal impact factor is a very useful tool for the evaluation of journals, but it must be used wisely. The decision on which journal to send your manuscript to should not rest solely on the IF. It is especially important to remember that a journal with a narrow focus (e.g., Diagnostic Molecular Pathology) may have a lower IF than a more broad-based journal (e.g., Journal of Pathology). Finally, researchers should look up other indicators for journal quality, like SNIP and Eigenfactor score, to get a better idea of journal prestige and influence. Contributors